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Sample records for perna perna bivalvia

  1. Influence of salinity on the physiological conditions in mussels, Perna perna and Perna viridis (Bivalvia: Mytilidae).

    PubMed

    Segnini de Bravo, Mary Isabel

    2003-06-01

    Perna genus was introduced to Venezuela, but nowadays, Perna perna and Perna viridis coexist and are commercially exploited from their natural beds. The aim of this work was to determine the effect of salinity on the physiological conditions of these species by studying RNA/DNA and Protein/DNA ratios. The organisms were collected from natural beds at La Esmeralda, Sucre State, Venezuela, and acclimatized for 15 days under laboratory conditions at 25 degrees C, 36 per thousand salinity, pH between 7 and 8 and more than 90% of oxygen saturation. Later, they were divided in two groups: for one group, the salinity concentration was increased (36 to 45 per thousand), and for the other, the salinity was decreased (36 to 15 per thousand). The rate of change was 1 per thousand every day. Ten organisms per group of both species were taken at each of 15, 20, 25, 30, 36, 40 y 45 per thousand salinity concentrations. Protein (colorimetric method) and nucleic acids (RNA and DNA by fluorometric method) concentrations were measured in the digestive gland, gills and adductor muscle tissues. Results indicate that P. perna can physiologically compensate the increase in salinity, but not when the salinity decreased, when proteins are the most needed macromolecules. The Protein/DNA index is directly related to salinity changes in both cases. P. viridis shows physiological compensation to salinity increases and decreases. The RNA/DNA index value in both cases supports this. Digestive gland and muscle tissues are the regulating tissues in both species. These results show that P. viridis has a higher degree of adaptability to salinity changes and, therefore, a greater potential for aquaculture than P. perna. PMID:15264566

  2. Pollution monitoring in Southeast Asia using biomarkers in the mytilid mussel Perna viridis (Mytilidae: Bivalvia).

    PubMed

    Nicholson, S; Lam, P K S

    2005-01-01

    Mytilid mussels have been extensively used in marine pollution monitoring programmes in temperate regions of the world although widespread subtropical representatives such as Perna viridis have only comparatively recently been utilised to monitor the sublethal effects of pollution in Southeast Asia. P. viridis is considered a subtropical equivalent of the temperate Mytilus sp. and has considerable potential for pollution monitoring throughout its geographical range. This paper reviews the current status of biomarkers in P. viridis and provides some recommendations on biological-effects monitoring to facilitate the assessment of coastal pollution in Southeast Asia. PMID:15607786

  3. Complete mitochondrial genome of the Asian green mussel Perna viridis (Bivalvia, Mytilidae).

    PubMed

    Li, Xiaoling; Wu, Xiangyun; Yu, Ziniu

    2012-10-01

    The complete mitochondrial (mt) genome of the Asian green mussel Perna viridis (16,627 bp), an economically important bivalve, was newly sequenced and annotated. P. viridis is the shortest and has a comparatively highest overall A+T content (68%) among six available genomes of marine mussels to date. The atp8 gene's length (49 a.a.) of the green mussel is unexpectedly greatly shorter than that of other marine mussels (87 a.a.). Comparison of the gene order demonstrated that the six marine mussels share no identical gene blocks although they belong to the same family, which indicates that this group should be a good model to study mtDNA evolution and mitochondria inheritance. PMID:22708864

  4. Use of sodium dodecyl sulfate and zinc sulfate as reference substances for toxicity tests with the mussel Perna perna (Linnaeus, 1758) (Mollusca: Bivalvia).

    PubMed

    Jorge, R A D L V C; Moreira, G S

    2005-06-01

    Effects of anthropogenic pollution have been observed at different trophic levels in the oceans, and toxicity tests constitute one way of monitoring these alterations. The present assay proposes the use of two reference substances, sodium dodecyl sulfate (SDS) and zinc sulfate, for Perna perna larvae. This common mussel on the Brazilian coast is used as a bioindicator and is of economic interest. The chronic static embryo-larval test of short duration (48 h) was employed to determine the NOEC, LOEC, and IC50 for SDS and zinc sulfate, as well as the coefficient of variation. Salinity, pH and un-ionized ammonia (NH3) and dissolved oxygen (DO) concentrations were measured to monitor water quality. The results demonstrated that the main alterations in veliger larvae are the development of only one shell, protruded mantle, malformed shell, formation of only part of a valve, clipped edges, uneven sizes and presence of a concave or convex hinge. NOEC values were lower than 0.25 mg L(-1) for zinc sulfate and 0.68 mg L(-1) for SDS. The coefficient of variation was 17.63% and 2.50% for zinc sulfate and SDS, respectively. PMID:15883100

  5. Ecocytological and toxicological responses to copper in Perna viridis (L.) (Bivalvia: Mytilidae) haemocyte lysosomal membranes.

    PubMed

    Nicholson, S

    2001-11-01

    Bivalve lysosomes are sites of intense intracellular digestion. Lysosomes accumulate many pollutants to high concentrations resulting in membrane destabilisation. Consequently, the elucidation of lysosomal membrane integrity utilising the neutral red assay has been used to good effect in pollution monitoring. Naturally occurring environmental stressors also have the potential to destabilise the membrane. Exposure to elevated copper concentrations and extremes of temperature, salinity, hypoxia, emersion and inadequate ration were investigated in haemocyte lysosomes from the tropical bivalve, Perna viridis. Elevated copper concentrations destabilised the membrane although responses were not entirely related to the exposure-concentration. Environmental stressors induced through higher thermal regimes (29 degrees C and 35 degrees C), hyposalinity (10-25/1000) and prolonged emersion elicited significant lysosomal membrane destabilisation. Hypoxia and inadequate ration did not significantly effect membrane stability. The haemocyte lysosomal membranes were generally resistant to exogenous alterations within normal ranges and only showed significant labilisation at environmental extremes. P. viridis haemocyte lysosomal membrane biomarkers should, therefore, prove robust to natural stressors when deployed in marine monitoring programmes and thus prove a valuable, rapid, cost-effective cytological marker of pollution. PMID:11680735

  6. A molecular phylogeny of the marine mussel genus Perna (Bivalvia: Mytilidae) based on nuclear (ITS1&2) and mitochondrial (COI) DNA sequences.

    PubMed

    Wood, Ann R; Apte, Smita; MacAvoy, Elizabeth S; Gardner, Jonathan P A

    2007-08-01

    A molecular phylogeny is presented for marine mussels of the genus Perna, based on nuclear (ITS1,ITS2) and mitochondrial (COI) DNA sequence data. The three generally recognised species (Perna viridis, Perna perna and Perna canaliculus) and one putative species (Perna picta) were each sampled from several locations within their known geographic distributions. A range of phylogenetic analyses was used to investigate the current taxonomic assignments, evolutionary relationships and the biogeographical history of the genus. The different analyses produced similar, well supported topologies and verified the monophyly of the genus with respect to five mytilid outgroup species. P. perna (Atlantic), P. viridis (Indo-West Pacific), and P. canaliculus (New Zealand) each formed distinct clades, confirming their specific status. Putative P. picta from North Africa clustered within the P. perna clade and is not regarded as a separate species. P. perna and P. canaliculus were the most closely related of the three species. Possible biogeographic explanations for the present species distributions are evaluated. PMID:17292632

  7. Biokinetics of cesium in Perna viridis

    SciTech Connect

    Yu, P.K.N.; Lam, P.K.S.; Ng, B.K.P.; Li, A.M.Y.

    2000-02-01

    The biokinetics of Cs in four compartments in the green-lipped mussel Perna viridis, namely, gill, viscera, adductor muscle, and foot, were studied. First-order linear differential equations were set up for these four compartments, and their solutions were used to fit the experimental data. The parameters governing the biokinetics, which depend on the elimination rate from each compartment and the transfer coefficient between compartments, were found. These are useful in understanding the physiology of Perna viridis, in predicting the activity of cesium in each compartment of Perna viridis from a contamination history, or in using Perna viridis as a sentinel organism for surveying and monitoring radioactive contamination. The results showed that the viscera should be represented by more than one compartment. Concentration factors for the four compartments and for Perna viridis were also determined, and these agreed well with reported values in the literature.

  8. Lysosomal membrane stability, phagocytosis and tolerance to emersion in the mussel Perna viridis (Bivalvia: Mytilidae) following exposure to acute, sublethal, copper.

    PubMed

    Nicholson, S

    2003-08-01

    The mytilid mussel Perna viridis is distributed throughout the Indo-Pacific region and is potentially a suitable candidate for biological effects (biomarker) monitoring in the subtropics. A suite of cytological and physiological responses to acute (48-72 h) copper exposures of 50-200 microgl(-1) were assessed in order to determine the suitability of P. viridis for marine pollution monitoring. Copper elicited significant destabilisation of the haemocyte lysosomal membranes and also impaired phagocytosis. Survival during emersion following exposure to copper was not related to the experimental copper exposures suggesting that higher metal concentrations may be required to interfere with anaerobic enzymes responsible for suppression of metabolism. Based on this preliminary study, cytological biomarkers evaluated in the haemocytes extracted from P. viridis should prove an effective non-destructive means of assessing metal pollution throughout the mussels subtropical range. PMID:12820995

  9. Partition of organochlorine concentrations among suspended solids, sediments and brown mussel Perna perna, in tropical bays.

    PubMed

    Galvao, Petrus; Henkelmann, Bernhard; Longo, Renan; Dorneles, Paulo Renato; Torres, João Paulo Machado; Malm, Olaf; Schramm, Karl-Werner

    2014-11-01

    For evaluating the brown mussel Perna perna as a sentinel organism regarding environmental concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), the present study reports original data on the relationship between the concentrations of these chemicals in bottom surface sediments, suspended solids (SS) and concentrations bioaccumulated by this bivalve. Three P. perna cultivation areas, located at three bays in southeastern Brazil were used in this study. The three estuaries are under different degrees of environmental impact. Variations in the OCP and PCB concentrations bioaccumulated by the bivalves tended to be similar to those observed in the sediment, but differed from those found in SS. This latter difference might suggest that the SS trapping apparatuses should have been left in place for approximately 60 days (not only 15 days). This longer period would allow the integration of the environmental variability of the OCP and PCB burden adsorbed to this compartment. Authors encourage future studies to evaluate P. perna exposure to OCPs and PCBs through the evaluation of sediment concentrations. PMID:25113178

  10. [Lipid and fatty acid profile of Perna viridis, green mussel (Mollusca: Bivalvia) in different areas of the Eastern Venezuela and the West Coast of Trinidad].

    PubMed

    Koftayan, Tamar; Milano, Jahiro; D'Armas, Haydelba; Salazar, Gabriel

    2011-03-01

    The species Perna viridis is a highly consumed species, which fast growth makes it an interesting aquaculture alternative for Venezuelan and Trinidad coasts. With the aim to contribute with its nutritional value information, this study analyzed lipid and fatty acid contents from samples taken in five locations from Eastern Venezuela and three from Trinidad West Coast. Total lipids were extracted and quantified, from a pooled sample of 100 organisms per location, by standard gravimetric methods, and their identification and quantification was done by TLC/FID (Iatroscan system). Furthermore, the esterified fatty acids of total lipid, phospholipids and triacylglycerols were identified and quantified by gas chromatography. Eastern Venezuela samples from Los Cedros, La Brea and Chaguaramas showed the highest total lipid values of 7.92, 7.74 and 7.53, respectively, and the minimum values were obtained for La Restinga (6.08%). Among lipid composition, Chacopata samples showed the lowest phospholipid concentration (48.86%) and the maximum values for cholesterol (38.87%) and triacylglycerols (12.26%); besides, La Esmeralda and Rio Caribe samples exhibited maximum phospholipids (88.71 and 84.93 respectively) and minimum cholesterol (6.50 and 4.42%) concentrations. Saturated fatty acids represented between 15.04% and 65.55% within total lipid extracts, with maximum and minimum values for La Esmeralda and Chacopata, respectively. Polyunsaturated results resulted between 7.80 and 37.18%, with higher values in La Brea and lower values in La Esmeralda. For phospholipids, saturated fatty acids concentrations varied between 38.81 and 48.68% for Chaguaramas and Chacopata samples, respectively. In the case of polyunsaturated fatty acids, these varied between non detected and 34.51%, with high concentrations in Los Cedros (27.97%) and Chaguaramas (34.51%) samples. For the triacylglycerols, the saturated fatty acids composition oscillated between 14.27 and 53.80% with low

  11. The brown mussel Perna perna (L., 1758) as a sentinel species for chlorinated pesticide and dioxin-like compounds.

    PubMed

    Galvao, Petrus; Henkelmann, Bernhard; Longo, Renan; Torres, João Paulo Machado; Malm, Olaf; Schramm, Karl-Werner

    2015-09-01

    To contribute to the use of the tropical brown mussel Perna perna as a sentinel species for organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB), the present study reports data on the toxicokinetics of these compounds in P. perna. Specifically, the authors present data on OCP and PCB bioaccumulation for eight sampling months from three bays (SE Brazil) and two transplant experiments (each 1 month long). Although seasonality is observed in the total lipid content of the whole soft tissue, with summer samples showing higher values, no such seasonality is observed in the OCP and PCB concentrations bioaccumulated by the mussel P. perna. Because no seasonal effect is observed in the annual OCP and PCB concentrations bioaccumulated by P. perna, the use of this species as a sentinel organism to monitor organochlorinated compounds is encouraged. One month of transplantation is not enough to allow the transplanted specimens to reach the concentrations observed in animals reared at the destination site. Nevertheless, P. perna showed a clear tendency to depurate the DDT metabolites p,p'-DDD and p,p'-DDE after 1 month of transplantation. PMID:25943516

  12. Biochemical responses in mussels Perna perna exposed to diesel B5.

    PubMed

    Nogueira, Lílian; Garcia, Danielly; Trevisan, Rafael; Sanches, Ana Letícia Madeira; da Silva Acosta, Daiane; Dafre, Alcir Luiz; Oliveira, Thiago Yukio Kikuchi; de Almeida, Eduardo Alves

    2015-09-01

    In Brazil B5 blend (5% biodiesel and 95% diesel oil) has been adopted as mandatory fuel since 2010 for automotive vehicles. Since little is known about the effects of B5 exposure can promote on antioxidant system of marine biota this study aimed to assess if B5 can generate modifications in antioxidant parameters of mussels Perna perna. To address this question mussels were exposed to two concentrations of B5 (0.01 mL L(-1) and 0.1 mL L(-1)) for 6h, 12h, 48 h and 168 h. Then the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) were evaluated in gills and digestive gland as well as the contents of glutathione (GSH) and lipid peroxidation by measuring the malondialdehyde concentration (MDA). In the gills, GST activity decreased after 48 h and GR after 12h of exposure to B5. In digestive glands, the activities of SOD, GPx and GR were changed due to treatments. GSH concentration increased in digestive gland after 6h and 12h and in gills after 48 h for B5 0.1 mL L(-1) and after 168 h in the digestive gland for B5 0.01 mL L(-1) treatment. No lipid peroxidation was detected. The integrated biomarker response index (IBR) evidenced a B5 effect in the digestive gland after 168 h of exposure. Regarding the experimental conditions and species used in this study, long-term exposure to B5 is apparently more likely to affect the parameters tested in P. perna mussels. PMID:25950138

  13. Characterization of ten highly polymorphic microsatellite loci for the intertidal mussel Perna perna, and cross species amplification within the genus

    PubMed Central

    2012-01-01

    Background The brown mussel Perna perna (Linnaeus, 1758) is a dominant constituent of intertidal communities and a strong invader with multiple non-native populations distributed around the world. In a previous study, two polymorphic microsatellite loci were developed and used to determine population-level genetic diversity in invasive and native P. perna populations. However, higher number of microsatellite markers are required for reliable population genetic studies. In this context, in order to understand P. perna origins and history of invasion and to compare population genetic structure in native versus invaded areas, we developed 10 polymorphic microsatellite markers. Findings Described microsatellite markers were developed from an enriched genomic library. Analyses and characterization of loci using 20 individuals from a population in Western Sahara revealed on average 11 alleles per locus (range: 5–27) and mean gene diversity of 0.75 (range: 0.31 - 0.95). One primer pair revealed possible linkage disequilibrium while heterozygote deficiency was significant at four loci. Six of these markers cross-amplified in P. canaliculus (origin: New Zealand). Conclusions Developed markers will be useful in addressing a variety of questions concerning P. perna, including dispersal scales, genetic variation and population structure, in both native and invaded areas. PMID:23039168

  14. Mussels (Perna perna) as bioindicator of environmental contamination by Cryptosporidium species with zoonotic potential.

    PubMed

    Mariné Oliveira, Geisi Ferreira; do Couto, Melissa Carvalho Machado; de Freitas Lima, Marcelo; do Bomfim, Teresa Cristina Bergamo

    2016-04-01

    Sources of contamination such as animal feces runoff, organic fertilizer application, and the release of partially treated or untreated sewage can lead to the contamination of aquatic environments by Cryptosporidium spp. The quality of mussels as food is closely related to the sanitary conditions of the marine environment where these bivalves are found. Marine mollusks are filter feeders that are able to retain Cryptosporidium oocysts in their tissue, thus functioning as bioindicators. A total of 72 pooled mussel samples of the species Perna perna were collected at two sites (A and B) in the municipality of Mangaratiba, Rio de Janeiro State, Brazil. Sampling involved removal of 30 mussels, from each collection site every month for one year. The 30 mussels from each sampling were then allocated into three groups of 10. Two Cryptosporidium spp. genes (18S and GP60) were targeted for DNA amplification from the samples obtained. After purification, all of the products obtained were sequenced and phylogenetic analyses were performed. Of the 72 samples analyzed using the nested-PCR for the 18S gene target, 29.2% were positive for the presence of Cryptosporidium spp. Of these samples, 52.4% were collected at site A (ie 11/21) and 47.6% at site B (ie 10/21). The 18S genes of all the samples considered positive for Cryptosporidium spp. were sequenced, and the following three species were identified: Cryptosporidium parvum, C. meleagridis, and C. andersoni. Three distinct C. parvum subtypes (IIaA19G2R2; IIaA20G2R2; IIaA20G3R2) were identified using the GP60 gene. More studies to evaluate the zoonotic potential of this species should be performed as both sampling locations contain human and/or animal fecal contaminants. PMID:26977402

  15. Mussels (Perna perna) as bioindicator of environmental contamination by Cryptosporidium species with zoonotic potential

    PubMed Central

    Mariné Oliveira, Geisi Ferreira; do Couto, Melissa Carvalho Machado; de Freitas Lima, Marcelo; do Bomfim, Teresa Cristina Bergamo

    2016-01-01

    Sources of contamination such as animal feces runoff, organic fertilizer application, and the release of partially treated or untreated sewage can lead to the contamination of aquatic environments by Cryptosporidium spp. The quality of mussels as food is closely related to the sanitary conditions of the marine environment where these bivalves are found. Marine mollusks are filter feeders that are able to retain Cryptosporidium oocysts in their tissue, thus functioning as bioindicators. A total of 72 pooled mussel samples of the species Perna perna were collected at two sites (A and B) in the municipality of Mangaratiba, Rio de Janeiro State, Brazil. Sampling involved removal of 30 mussels, from each collection site every month for one year. The 30 mussels from each sampling were then allocated into three groups of 10. Two Cryptosporidium spp. genes (18S and GP60) were targeted for DNA amplification from the samples obtained. After purification, all of the products obtained were sequenced and phylogenetic analyses were performed. Of the 72 samples analyzed using the nested-PCR for the 18S gene target, 29.2% were positive for the presence of Cryptosporidium spp. Of these samples, 52.4% were collected at site A (ie 11/21) and 47.6% at site B (ie 10/21). The 18S genes of all the samples considered positive for Cryptosporidium spp. were sequenced, and the following three species were identified: Cryptosporidium parvum, C. meleagridis, and C. andersoni. Three distinct C. parvum subtypes (IIaA19G2R2; IIaA20G2R2; IIaA20G3R2) were identified using the GP60 gene. More studies to evaluate the zoonotic potential of this species should be performed as both sampling locations contain human and/or animal fecal contaminants. PMID:26977402

  16. Differential metallothionein, reduced glutathione and metal levels in Perna perna mussels in two environmentally impacted tropical bays in southeastern Brazil.

    PubMed

    Lavradas, Raquel T; Rocha, Rafael C C; Bordon, Isabella C A C; Saint'Pierre, Tatiana D; Godoy, José M; Hauser-Davis, Rachel A

    2016-07-01

    Mussel farming is an important economic activity in Brazil, and these organisms are consumed by the majority of the population in most coastal zones in the country. However, despite the increasing pollution of aquatic ecosystems in Brazil, little is known about the biochemical activity in mussels in response to metal exposure. In this context, the aim of the present study was to investigate metal and metalloid exposure effects in Perna perna mussels, by determining metal levels, the induction of metallothionein (MT) synthesis, and oxidative stress, in the form of reduced glutathione (GSH) in 3 contaminated areas from the Guanabara Bay in comparison to a reference site, Ilha Grande Bay, both in summer and winter. Metal and metalloid concentrations were also compared to Brazilian and international guidelines, to verify potential health risks to human consumers. Mussels from all sampling sites were shown to be improper for human consumption due to metal contamination, including Ilha Grande Bay, which has previously been considered a reference site. Several statistically significant correlations and seasonal differences were observed between MT, GSH and metals and metalloids in both analyzed tissues. A Discriminant Canonical Analysis indicated that the digestive gland is a better bioindicator for environmental contamination by metals and metalloids in this species and offers further proof that MT variations observed are due to metal exposure and not oxidative stress, since GSH influence for both muscle tissue and the digestive glands was non-significant in this analysis. These results show that P. perna mussels are an adequate sentinel species for metal contamination with significant effects on oxidative stress and metal exposure biomarkers. To the best of our knowledge, this is the first study to report metals, metalloids, MT and GSH levels in the muscle tissue of this species. PMID:26994306

  17. Investigation of thermostable metalloproteins in Perna perna mussels from differentially contaminated areas in Southeastern Brazil by bioanalytical techniques.

    PubMed

    Lavradas, Raquel Teixeira; Rocha, Rafael Christian Chávez; Saint' Pierre, Tatiana Dillenburg; Godoy, José Marcus; Hauser-Davis, Rachel Ann

    2016-03-01

    Metallomic studies regarding environmental contamination by metals are of value in elucidating metal uptake, trafficking, accumulation and metabolism in biological systems. Many proven bioindicator species, such as bivalves, have not yet, however, been well-characterized regarding their metalloprotein expression in response to environmental contaminants. In this context, the aim of the present study was to investigate metalloprotein expressions in the thermostable protein fraction of muscle tissue and digestive glands from mussels (Perna perna) from three differentially metal-contaminated sites in Southeastern Brazil in comparison with a reference site. The thermostable protein fractions were analyzed by SDS-PAGE and SEC-HPLC-ICP-MS. Metal content was also determined in both the crude and the purified extracts. Several inter-organ differences were observed, which is to be expected, while inter-site differences regarding thermostable protein content were also verified, indicating accumulation of these elements in muscle tissue and digestive glands and disruption of homeostasis of essential elements, with detoxification attempts by metal-bound proteins, since all metalloproteins present in both matrices eluted bound to at least one non-essential metal. These results are also noteworthy with regard to the adopted reference site, that also seems to be contaminated by toxic metals. PMID:26854248

  18. Monoamine content during the reproductive cycle of Perna perna depends on site of origin on the Atlantic Coast of Morocco

    PubMed Central

    Klouche, Mounia S.; De Deurwaerdère, Philippe; Dellu-Hagedorn, Françoise; Lakhdar-Ghazal, Nouria; Benomar, Soumaya

    2015-01-01

    Bivalve molluscs such as Perna perna display temporal cycles of reproduction that result from the complex interplay between endogenous and exogenous signals. The monoamines serotonin, dopamine and noradrenaline represent possible endocrine and neuronal links between these signals allowing the molluscs to modulate reproductive functions in conjunction with environmental constraints. Here, we report a disruption of the reproductive cycle of mussels collected from two of three sites along the Moroccan atlantic coast soiled by industrial or domestic waste. Using high pressure liquid chromatography, we show that the temporal pattern of monoamine content in the gonads, pedal and cerebroid ganglia varied throughout the reproductive cycle (resting, developing, maturing, egg-laying) of mussels from the unpolluted site. Marked modification of monoamine tissue content was found between sites, notably in noradrenaline content of the gonads. Discriminant statistics revealed a specific impact of mussel location on the temporal variations of noradrenaline and serotonin levels in gonads and cerebroid ganglia. Correlation analyses showed profound and temporal changes in the monoamine content between organs and ganglia, at the two sites where the reproduction was disrupted. We suggest that environmental constraints lead to profound changes of monoaminergic systems, which thereby compromises the entry of mussels into their reproductive cycle. PMID:26349428

  19. Comparative studies on uptake pathway of cadmium by Perna viridis

    NASA Astrophysics Data System (ADS)

    Fang, Zhanqiang

    2006-01-01

    Experiments were designed to expose the filter-feeding bivalve Perna viridis to different Cd-contaminated water environments in order to compare the different pathways through which Cd is accumulated. Results show that mussels can accumulate Cd through seawater, food, sediment and suspended particle pathways in a short period of time. Mussels' uptake of Cd through the seawater pathway reaches the highest concentration approximately 3 and 9 times larger than through the algae and sediment pathways respectively after 7 d. This indicates that the Cd-accumulation through seawater is most efficient. Results also indicate that the uptake directly through contaminated algae, particles or sediments ingested by mussels is less important when compared with the uptake of Cd by mussels through the seawater pathway. Metal uptake pathways and mechanisms of bioaccumulation by marine bivalve are also discussed in this paper.

  20. In vitro modulation of inflammatory cytokine and IgG levels by extracts of Perna canaliculus

    PubMed Central

    Mani, Sachin; Lawson, John W

    2006-01-01

    Background Inflammation is a predominant characteristic of autoimmune diseases which is characterized by the increased expression of pro-inflammatory cytokines. Soon to be published work from our laboratory has shown that ingestion of Perna canaliculus prevents the development of autoimmune diseases such as Systemic Lupus Erythematosus and rheumatoid arthritis in laboratory animals. The current paper attempts to illustrate how Perna can alleviate inflammation by modulating inflammatory cytokines, cyclooxygenase enzymes and Immunoglobulin-G (IgG) levels. Methods In the present study, hydrochloric acid [HCl] and Tween-20 were used to develop extracts of Perna. These extracts were assayed for protein content. Increasing concentrations of these extracts were then tested in cell culture for modulation of inflammatory cytokine, cyclooxygenase enzymes and IgG levels. Parallel tests were run using an available glycogen extract of Perna as a comparison to our in-house laboratory preparations. Results Tween-20 Perna extracts were found to be more stable and less toxic in cell culture than HCl digest of Perna. They also assayed higher in protein content that HCl extracts. Although both extracts inhibited IgG production in V2E9 hybridomas, Tween-20 extracts were more consistent in IgG suppression than HCl extracts. Overall Tween-20 extracts effectively decreased levels of TNF-α, IL-1, IL-2 and IL-6 as observed using cytokine bioassays. Twenty micrograms of Tween-20 Perna extracts induced such significant decreases in inflammatory cytokine production that when tested on sensitive cell lines, they very nearly abolished the decrease in viability induced by these cytokines. Tween-20 extracts effectively inhibited both COX-1 and COX-2 cyclooxygenase activity. As a comparison, the glycogen extract also demonstrated a similar though weaker effect on COX-1 and COX-2 enzymes. The active components of both extracts (Tween-20 and glycogen) were observed to possess molecular weights

  1. Food availability and reproduction affects lipid and fatty acid composition of the brown mussel, Perna perna, raised in suspension culture.

    PubMed

    Narváez, Mirle; Freites, L; Guevara, M; Mendoza, J; Guderley, H; Lodeiros, C J; Salazar, G

    2008-02-01

    We examined the influence of the reproductive cycle and environmental factors on variations of the condition index (CI), tissue dry mass, shell size, total lipid content, and relative percent of fatty acids in the mussel, Perna perna. Spat or juveniles were reared to commercial size (70 mm) in suspension culture in the Golfo de Cariaco, Venezuela between May and October 2004. The dry mass of soft tissues and shell, a visual assessment of gonadal status and the organism lipid profile were established every fortnight. In parallel, we measured the environmental conditions, following chlorophyll a, salinity, temperature and seston levels. After an initial decrease, the CI rose and remained high until August after which it decreased continuously until October. Total lipid values also decreased initially, after which they showed two periods of rapid recuperation and depletion, the first between May and August and the second between August and October. Similar tendencies were noted in the fatty acids, C18:3n-3, C18:4n-3 and C22:6n-3. Correlation analysis found no significant relationships between environmental parameters and the variations in total lipids. However, significant correlations were noted between fatty acids and specific environmental parameters. In particular, temperature was inversely correlated with C14:0, C16:1n-7, C18:0, C18:1n-9 and 20:5n-3. Chlorophyll a was positively correlated with C14:0, C16:1n-7, C18:1n-7, C18:4n-3 and 20:4n-6. On the other hand, gametogenesis had an effect on C14:0, C16:1n-7, C18:1n-9 and C18:1n-7, while spawned and gonadal regression states had an effect on fatty acid 20:4n-6. Temperature and chlorophyll a levels strongly influenced the proportion of mussels spawning, suggesting that their influence upon lipid composition may be secondary to their impact upon reproduction. Despite the thermal stability of this tropical system, the lipid composition of mussels changed markedly during the study, reflecting the central role of diet

  2. Detailed Distribution of Lipids in Greenshell™ Mussel (Perna canaliculus)

    PubMed Central

    Miller, Matthew R.; Pearce, Luke; Bettjeman, Bodhi I.

    2014-01-01

    Greenshell™ mussels (GSM–Perna canaliculus) are a source of omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA). Farmed GSM are considered to be a sustainable source of LC-PUFA as they require no dietary inputs, gaining all of their oil by filter-feeding microorganisms from sea water. GSM oil is a high-value product, with a value as much as 1000 times that of fish oils. GSM oil has important health benefits, for example, anti-inflammatory activity. It also contains several minor lipid components that are not present in most fish oil products, and that have their own beneficial effects on human health. We have shown the lipid content of the female GSM (1.9 g/100 g ww) was significantly greater than that of the male (1.4 g/100 g ww). Compared with male GSM, female GSM contained more n-3 LC-PUFA, and stored a greater proportion of total lipid in the gonad and mantle. The higher lipid content in the female than the male GSM is most likely related to gamete production. This information will be useful to optimize extraction of oils from GSM, a local and sustainable source of n-3 LC-PUFA. PMID:24732016

  3. Glycosylated Hydroxytryptophan in a Mussel Adhesive Protein from Perna viridis*

    PubMed Central

    Zhao, Hua; Sagert, Jason; Hwang, Dong Soo; Waite, J. Herbert

    2009-01-01

    The 3,4-dihydroxyphenyl-l-alanine (Dopa)-containing proteins of mussel byssus play a critical role in wet adhesion and have inspired versatile new synthetic strategies for adhesives and coatings. Apparently, however, not all mussel adhesive proteins are beholden to Dopa chemistry. The cDNA-deduced sequence of Pvfp-1, a highly aromatic and redox active byssal coating protein in the green mussel Perna viridis, suggests that Dopa may be replaced by a post-translational modification of tryptophan. The N-terminal tryptophan-rich domain of Pvfp-1 contains 42 decapeptide repeats with the consensus sequences ATPKPW1TAW2K and APPPAW1TAW2K. A small collagen domain (18 Gly-X-Y repeats) is also present. Tandem mass spectrometry of isolated tryptic decapeptides has detected both C2-hexosylated tryptophan (W1) and C2-hexosylated hydroxytryptophan (W2), the latter of which is redox active. The UV absorbance spectrum of W2 is consistent with 7-hydroxytryptophan, which represents an intriguing new theme for bioinspired opportunistic wet adhesion. PMID:19584055

  4. MOOCs from the Viewpoint of the Learner: A Response to Perna et al. (2014)

    ERIC Educational Resources Information Center

    Wiebe, Eric; Thompson, Isaac; Behrend, Tara

    2015-01-01

    This response to Perna et al. provides an alternate approach to research on massive open online courses (MOOCs). We argue that a student-centered, theory-driven conceptualization and methodological approaches allow us to move beyond descriptive statistics and into a deeper understanding of MOOC learners. Examples using a teacher development MOOC…

  5. DiPerna-Lions Flow for Relativistic Particles in an Electromagnetic Field

    NASA Astrophysics Data System (ADS)

    Jabin, P.-E.; Masmoudi, N.

    2015-09-01

    We show the existence and uniqueness of a DiPerna-Lions flow for relativistic particles subject to a Lorentz force in an electromagnetic field. The electric and magnetic fields solve the linear Maxwell system in the vacuum but for singular initial conditions which are only in the physical energy space. As the corresponding force field is only in L 2, we have to perform a careful analysis of the cancellations over a trajectory.

  6. Trace metals in the brown mussel Perna perna from the coastal waters off Yemen (Gulf of Aden): how concentrations are affected by weight, sex, and seasonal cycle.

    PubMed

    Sokolowski, A; Bawazir, A S; Wolowicz, M

    2004-01-01

    The effects of seasonal cycle, sex of individuals, and changes of soft tissues weight on accumulated trace metal concentrations (Cd, Cu, Fe, Mn, Pb, Zn) were examined in the brown mussel Perna perna collected monthly from a natural rocky habitat in the coastal waters off Yemen, the Gulf of Aden, for a period of ten months. Basic hydrological parameters were recorded simultaneously. All metals analyzed displayed seasonal fluctuations with different temporal patterns and variable amplitudes. Similar seasonal cycles were observed for Cu, Mn, and Pb with an increase in accumulated concentration during the rainy period (NE monsoon), and a decrease thereafter. The concentrations of Cu, Mn, and partially Pb appeared to be related to environmental changes, the concentration of Pb possibly also being related to changes in body weight. Accumulated concentrations of Cu and Mn thus seem to reflect actual metal bioavailability in the ecosystem quite efficiently. The tissue levels of Fe and Cd changed inversely to fluctuations in body weight with additional variation due to monsoon-related environmental changes. The behaviors of Fe and Cd are therefore driven by seasonally changing body weight with a considerable contribution of external factors including fluctuations in hydrological conditions and metal exposure. The Zn concentrations tended to increase gradually throughout most of the year regardless of its concentration in the environment. Zinc is considered to be mainly regulated by physiological mechanisms in the mussel, making its accumulated metal concentration independent to some degree of environmental levels. Significant differences in trace metal concentrations between sexes (in favour of females) might have resulted from more intense formation of reproductive tissues and metal accumulation in sexual products of females during the prespawning and spawning periods. PMID:15025166

  7. Bioaccumulation and depuration of some trace metals in the mussel, Perna viridis (Linnaeus)

    SciTech Connect

    Lakshmanan, P.T. ); Nambisan, P.N.K. )

    1989-07-01

    Bivalves are well known for their ability to concentrate heavy metals in their tissue from environmental water. Experimental studies on the accumulation of these pollutants by molluscs have been extensively conducted. The depuration of accumulated metals in a toxicant free medium has also been studied. Bivalve molluscs may form useful tools in monitoring heavy metal pollution. However, such studies are scant in tropical species. This paper reports the bioaccumulation and depuration of Hg, Cu, Zn and Pb by the mussel Perna viridis (Linnaeus) from seawater and explores its suitability as an indicator organism for metal pollution.

  8. Heavy metals in green mussel (Perna viridis) and oysters (Crassostrea sp.) from Trinidad and Venezuela.

    PubMed

    Rojas de Astudillo, L; Chang Yen, I; Agard, J; Bekele, I; Hubbard, R

    2002-05-01

    Heavy metal concentrations were monitored in edible soft tissues of shellfish from Trinidad and Venezuela. Oysters (Crassostrea sp.) and the green mussel (Perna viridis), which is a recently transplanted species to the Caribbean from the Far East, were collected at six locations in Venezuela and five in Trinidad, the latter along the coast line of the Gulf of Paria. Simple and low-cost methods of analysis were optimized and validated using standard reference materials. Cadmium, copper, lead, nickel, and zinc were analyzed by flame atomic absorption spectrometry. Mercury was determined by cold-vapor atomic absorption spectrometry. The present study has confirmed that oysters have a much greater capacity for accumulation of copper and zinc than does green mussel. In addition, concentrations of copper and zinc in oysters (Crassostrea sp.) at many of the sites in the Gulf of Paria exceeded local and international standards, whereas green mussel P. viridis contained generally acceptable levels for human consumption. PMID:11994781

  9. Proteomic profile in Perna viridis after exposed to Prorocentrum lima, a dinoflagellate producing DSP toxins.

    PubMed

    Huang, Lu; Zou, Ying; Weng, Hui-wen; Li, Hong-Ye; Liu, Jie-Sheng; Yang, Wei-Dong

    2015-01-01

    In the current study, we compared protein profiles in gills of Perna viridis after exposure to Prorocentrumlima, a dinoflagellate producing DSP toxins, and identified the differential abundances of protein spots using 2D-electrophoresis. After exposure to P. lima, the level of okadaic acid (a main component of DSP toxins) in gills of P. viridis significantly increased at 6 h, but mussels were all apparently healthy without death. Among the 28 identified protein spots by MALDI TOF/TOF-MS, 12 proteins were up-regulated and 16 were down-regulated in the P. lima-exposed mussels. These identified proteins were involved in various biological activities, such as metabolism, cytoskeleton, signal transduction, response to oxidative stress and detoxification. Taken together, our results indicated that the presence of P. lima caused DSP toxins accumulation in mussel gill, and might consequently induce cytoskeletonal disorganization,oxidative stress, a dysfunction in metabolism and ubiquitination/proteasome activity. PMID:25463732

  10. Monitoring of organochlorine pesticides residues in green mussels (Perna viridis) from the coastal area of Thailand.

    PubMed

    Boonyatumanond, Ruchaya; Jaksakul, Areerat; Puncharoen, Pornthip; Tabucanon, Monthip Sriratana

    2002-01-01

    The utilization of organochlorine pesticides for pest control chemical has been of great interest on residue contamination from biological organisms in the environment. Green mussel (Perna viridis) samples were monitored as bioindicators for assessment of the water quality in coastal waters along the Gulf of Thailand. Thirty-six samples were collected from 12 stations during 1997-1999 and analysed for 26 organochlorine pesticide compounds. This paper focuses on the contamination of organochlorine pesticide residues in green mussel (P. viridis) during 1997-1999. The limit of detection of all organochlorine pesticides compounds was at the range of 0.1-8.3 ng g(-1) wet weight and recovery 75-95%. The concentration of organochlorine pesticides residues in green mussel was lower than the maximum residue limit for aquatic animals as recommended by the Ministry of Public Health of Thailand. The trend of organochlorine pesticide residue contamination in this area decreased from 1989 to 1999. PMID:12152831

  11. Metallothionein cDNA, promoter, and genomic sequences of the tropical green mussel, Perna viridis.

    PubMed

    Khoo, H W; Patel, K H

    1999-09-01

    The primary structure of the cDNA and metallothionein (MT) genomic sequences of the tropical green mussel (Perna viridis) was determined. The complete cDNA sequences were obtained using degenerate primers designed from known metallothionein consensus amino acid sequences from the temperate species Mytilus edulis. The amino acid sequences of P. viridis metallothionein deduced from the coding region consisted of 72 amino acids with 21 cysteine residues and 9 Cys-X-Cys motifs corresponding to Type I MT class of other species. Two different genomic sequences coding for the same mRNA were obtained. Each putative gene contained a unique 5'UTR and two unique introns located at the same splice sites. The promoters for both genes were different in length and both contained metal responsive elements and active protein-binding sites. The structures of the genomic clones were compared with those of other species. J. Exp. Zool. 284:445-453, 1999. PMID:10451422

  12. Characterization of eight novel microsatellite markers in the green-lipped mussel Perna viridis (Mytilidae).

    PubMed

    Cao, Y Y; Li, Z B; Li, Q H; Chen, X J; Chen, L; Dai, G

    2013-01-01

    The green lipped mussel, also known as the Asian green mussel (Perna viridis) is a fast reproducing and valuable food source, but it is also considered an invasive species and can clog and damage pipes and marine equipment. Eight novel polymorphic microsatellite loci for P. viridis were isolated and characterized. Microsatellite polymorphism was evaluated in 30 individuals collected from Xiamen, China. The number of alleles per locus and the polymorphism information content ranged from 2 to 5 and from 0.3092 to 0.7031, respectively. The observed and expected heterozygosities were 0.1538-0.8400 and 0.1448-0.6833, respectively. The loci identified in this study could provide a useful tool for the genetic population structure analysis of P. viridis. PMID:23420359

  13. Water chemistry influences the toxicity of silver to the green-lipped mussel Perna viridis.

    PubMed

    Vijayavel, Kannappan

    2010-08-01

    The study determined the influence and relative importance of water chemistry parameters (pH, alkalinity, hardness) on the acute toxicity of silver to the green mussel Perna viridis. A preliminary bioassay revealed that 4 mg L(-1) of silver caused 50% mortality (LC50) in 96 h for mussels placed in seawater with pH 8.5, hardness 1,872 mg L(-1), and alkalinity 172 mg L(-1). Mortality of mussels increased with decreasing pH and increasing hardness and alkalinity variables. In contrast the mortality decreased with increasing pH and decreasing hardness and alkalinity values. The water chemistry also affected the concentration of silver in experimental seawater and bioaccumulation of silver in mussels. The results revealed that the chemical properties of seawater must be considered while conducting toxicity tests with metals like silver. The possible explanations for the influence of water chemistry on silver toxicity to P. viridis are discussed. PMID:19565346

  14. Effects of mercury and lead on tissue glutathione of the green mussel, Perna viridis L.

    SciTech Connect

    Yan, T.; Teo, L.H.; Sin, Y.M.

    1997-05-01

    Glutathione (GSH) is the major non-protein thiol in animals, and involved in a number of important physiological and detoxification processes. It has been suggested that this tripeptide protects thiol groups in proteins from oxidation, functions as an intracellular redox buffer and serves as a reservoir of cysteine. Tissue GSH is also known to be involved in the metabolism and detoxification of endogenous and exogenous substances, including the binding of inorganic mercury ions. Therefore, a change in the amount of GSH in tissues may be considered to reflect the effects of deposited mercury on tissue function. The functions of the tripeptide have been studied less thoroughly in invertebrates than in vertebrates. The purpose of this study was to determine whether there were changes in the amounts of tissue GSH in the green mussel, Perna viridis, at various time intervals after metal exposure. 22 refs., 1 fig., 1 tab.

  15. Heavy metals concentration relationship with Perna viridis physical properties in Mengkabong Lagoon, Sabah, Malaysia.

    PubMed

    Abdullah, Noraini; Tair, Rohana; Abdullah, Mohd Harun

    2014-01-01

    Perna viridis (P. viridis) has been identified as a good biological indicator in identifying environmental pollution, especially when there are various types of Heavy Metals Accumulations (HMA) inside its tissue. Based on the potential of P. viridis to accumulate heavy metals and the data on its physical properties, this study proffers to determine the relationships between both properties. The similarities of the physical properties are used to mathematical model their relationships, which included the size (length, width, height) and weight (wet and dry) of P. viridis, whilst the heavy metals are focused on concentrations of Pb, Cu, Cr, Cd and Zn. The concentrations of metal elements are detected by using Flame Atomic Adsorption Spectrometry. Results show that the mean concentration of Pb, Cu, Cr, Cd, Zn, length, width, height, wet weight and dry weight are: 1.12 +/- 1.00, 2.36 +/- 1.65, 2.12 +/- 2.74, 0.44 +/- 0.41 and 16.52 +/- 10.64 mg kg(-1) (dry weight), 105.08 +/- 14.35, 41.64 +/- 4.64, 28.75 +/- 3.92 mm, 14.56 +/- 3.30 and 2.37 +/- 0.86 g, respectively. It is also found out that the relationships between the Heavy Metals Concentrations (HMA) and the physical properties can be represented using Multiple Linear Regressions (MLR) models, relating that the HMA of Zinc has affected significantly the physical growth properties of P. viridis. PMID:24783779

  16. Organochlorine pesticides in green mussel, Perna viridis, from the Cienfuegos Bay, Cuba.

    PubMed

    Alonso-Hernández, Carlos Manuel; Gómez-Batista, Miguel; Cattini, Chantal; Villeneuve, Jean-Pierre; Oh, Jae

    2012-11-01

    The green mussel, Perna viridis, was used to measure bioaccumulated levels of organochlorine pesticides in the marine environment of Cuba. Samples were collected in the Cienfuegos Bay between January and December 2010. The organochlorine pesticides (i.e. DDT, Dieldrin, Chlordane, Endosulfan, HCB, Aldrin, Heptachlor and Lindane) were quantified by gas chromatography. The sum of all organochlorine pesticides in P. viridis was 6.31 ng g(-1). The concentration ranged from 3.53 to 4.42 ng g(-1) dry weight (dw) for DDTs (i.e. sum of pp' DDT, pp' DDD, op' DDE and pp' DDE); 1.7-1.9 ng g(-1) dw for Dieldrin; 0.17-0.20 ng g(-1) dw for Chlordanes; 0.14-0.16 ng g(-1) dw for Endosulfan; 0.11-0.17 ng g(-1) dw for HCB; 0.07-0.11 ng g(-1) dw for Aldrin; 0.046-0.054 ng g(-1) dw for Heptachlor and 0.035-0.039 ng g(-1) dw for Lindane. These levels can be considered as low when compared to reported values from similar studies conducted elsewhere in the world. The concentrations of all organochlorines residues detected in this study fell below the EU Maximum Residue Limits. PMID:22996652

  17. Toxicity Profile of a Nutraceutical Formulation Derived from Green Mussel Perna viridis

    PubMed Central

    Joseph, Deepu; Chakkalakal, Selsa J.

    2014-01-01

    The short-term (acute) and long-term (subchronic) toxicity profile, mean lethal dose 50 (LD50), and no-observed-adverse-effect level (NOAEL) of a nutraceutical formulation developed from green mussel Perna viridis, which showed in vitro and in vivo anti-inflammatory properties, were evaluated in the present study. The formulation was administered to the male and female Wistar rats at graded doses (0.5, 1.0, and 2.5 g/kg body weight) for two weeks of acute toxicity study and 0.5, 1.0, and 2.0 g/kg body weight for 90 days in subchronic toxicity study. The LD50, variations in clinical signs, changes in body weight, body weight, food/water consumption, organ weight (liver, kidney, spleen, and brain), hematology, serum chemistry, and histopathological changes were evaluated. The LD50 of the formulation was 5,000 mg/kg BW. No test article related mortalities as well as change in body weight, and food and water consumption were observed. No toxicity related significant changes were noted in renal/hepatic function, hematological indices, and serum biochemical parameters between the control and treated groups. Histopathological alterations were not observed in the vital organs of rats. The subchronic NOAEL for the formulation in rats is greater than 2000 mg/kg. This study demonstrated that the green mussel formulation is safe to consume without any adverse effects in the body. PMID:24995298

  18. Genetic characterization of Perna viridis L. in peninsular Malaysia using microsatellite markers.

    PubMed

    Ong, C C; Yusoff, K; Yap, C K; Tan, S G

    2009-08-01

    A total of 19 polymorphic microsatellite loci were used to analyse levels of genetic variation for 10 populations of Perna viridis L. collected from all over peninsular Malaysia. The populations involved in this study included Pulau Aman in Penang, Tanjung Rhu in Kedah, Bagan Tiang in Perak, Pulau Ketam in Selangor, Muar, Parit Jawa, Pantai Lido and Kampung Pasir Puteh in Johore, and Kuala Pontian and Nenasi in Pahang state. The number of alleles per locus ranged from two to seven, with an average of 3.1. Heterozygote deficiencies were observed across all the 10 populations. Characterization of the populations revealed that local populations of P. viridis in peninsular Malaysia were genetically similar enough to be used as a biomonitoring agent for heavy metal contamination in the Straits of Malacca. Cluster analysis grouped the P. viridis populations according to their geographical distributions with the exception of Parit Jawa. The analysis also revealed that P. viridis from the northern parts of peninsular Malaysia were found to be the most distant populations among the populations of mussels investigated and P. viridis from the eastern part of peninsular Malaysia were closer to the central and southern populations than to the northern populations. PMID:19700853

  19. Responses of the green-lipped mussel Perna viridis (L.) to suspended solids.

    PubMed

    Shin, P K S; Yau, F N; Chow, S H; Tai, K K; Cheung, S G

    2002-01-01

    Laboratory experiments were conducted to investigate the lethal and sublethal effects of suspended solids on the survival and physiological, behavourial and morphological changes of the green-lipped mussel Perna viridis collected from Tolo Harbour, Hong Kong. Results showed that P. viridis survived in all test conditions of suspended solids from 0 to 1,200 mg/l over a period of 96 h. Physiological responses of the green-lipped mussel under 14-d exposure of suspended solids from 0 to 600 mg/l, followed by 14-d recovery in natural seawater, revealed no significant changes (p > 0.05) in oxygen consumption and dry gonosomatic index for treatments in different concentrations of suspended solids and exposure time. Changes in clearance rate were only found to be significant (p < 0.001) with exposure time. Responses in behavourial and morphological changes of the green-lipped mussel were also studied under similar experimental treatments and exposure time. Byssus production was significantly (p < 0.001) related to exposure time. Gill damage, however, was significantly greater in treatments (p < 0.001). Present findings suggested that P. viridis could tolerate a high level of suspended solids in the laboratory. There were dose-dependent effects of suspended solids on morphology of gill filaments. Implications of survival and responses of the green-lipped mussel to suspended solids in the marine environment are discussed. PMID:12398380

  20. Application of oxidative stress indices in natural populations of Perna viridis as biomarker of environmental pollution.

    PubMed

    Jena, K B; Verlecar, X N; Chainy, G B N

    2009-01-01

    Oxidative stress indices were measured in gills and digestive glands of Perna viridis collected from three coastal locations in Goa i.e., Bambolim, Marmugao Harbour and Malim. In addition to lipid peroxidation, the activities of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione S-transferase and two non-enzymatic antioxidants (ascorbic acid and reduced glutathione) were investigated in order to understand their variation with respect to pollution status of the sampling locations. We observed a significant increase in lipid peroxidation and antioxidant enzymes of both the tissues at Mormugao Harbour and Malim, suggesting that the animals at these two locations are at higher level of oxidative stress as compared to those at Bambolim. Conversely, low levels of non-enzymatic antioxidants such as ascorbic acid and reduced glutathione, observed at Mormugao Harbour and Malim indicate that the animals may use these compounds to counteract stress in the tissues. This study shows that changes in lipid peroxidation, superoxide dismutase, catalase, glutathione reductase, glutathione S-transferase and reduced glutathione in tissues of P. viridis can be used as molecular biomarkers in environmental monitoring programs. PMID:18849055

  1. Activation of prophenoloxidase in the plasma and haemocytes of the marine mussel Perna viridis Linnaeus.

    PubMed

    Asokan, R; Arumugam, M; Mullainadhan, P

    1997-01-01

    Phenoloxidase activity was detected in plasma and haemocytes of the marine mussel Perna viridis. This enzyme exists as a proenzyme, prophenoloxidase (proPO), in both these haemolymph fractions and could be activated in vitro by exogenous proteases (trypsin and alpha-chymotrypsin) and a detergent (sodium dodecyl sulphate). In addition, laminarin (a polymer of beta-1,3 glucan) and bacterial lipopolysaccharides (LPSa) effectively triggered proPO activation in these haemolymph fractions. The activation of proPO by non-self molecules was dependent upon calcium ions at a low concentration. This activation process appeared to involve a limited proteolysis, since serine protease inhibitors (soybean trypsin inhibitor, benzamidine or p-nitrophenyl-p'-guanidinobenzoate) suppressed conversion of proPO to the active enzyme. This study demonstrates the selective response of plasma and haemocytic proPO to activation by different types of bacterial LPS tested and suggests that proPO system in both plasma and haemocytes of P. viridis serves an important function in non-self recognition and host immune reactions. PMID:9241484

  2. Induction, adaptation and recovery of lysosomal integrity in green-lipped mussel Perna viridis.

    PubMed

    Fang, J K H; Wu, R S S; Zheng, G J; Lam, P K S; Shin, P K S

    2008-01-01

    Biomarkers are generally applied to detect pollution in environmental monitoring. Such biological responses should accurately reflect the stress over time in a quantitative manner. As such, the initial and maximum responses induced by stress, as well as adaptation and recovery of these biomarkers, need to be fully understood or else erroneous false-negative or false-positive may be arrived. However, most of the biomarker studies only provided information on initially induced responses under different concentrations of toxicants, while biological adaptation and recovery were poorly known. In this study, the time required for induction, adaptation and recovery of lysosomal integrity in green-lipped mussel Perna viridis upon exposure to benzo[a]pyrene was investigated over a period of 62 days. Maximum induction occurred on day 6 when lysosomal integrity was significantly reduced by 51%, and no further change or adaptation was detected thereafter. When mussels were depurated in clean seawater after 18 days of exposure to benzo[a]pyrene, a gradual recovery was observed, with lysosomal integrity returning to its background level and showing a complete recovery after 20 days of depuration. Lysosomal integrity was significantly correlated with the body burden concentrations of benzo[a]pyrene and condition index of the mussels. The relatively fast induction (6 days) and recovery (20 days) without apparent adaptation suggested that lysosomal integrity in P. viridis can serve as a good biomarker in biomonitoring, as its response is not likely to generate both false-negative and false-positive results. PMID:18466928

  3. Radioprotection against DNA damage by an extract of Indian green mussel, Perna viridis (L).

    PubMed

    Kumaran, Sreekumar P; Kutty, Binoj C; Chatterji, Anil; Subrayan, Parameswaran P; Mishra, Kaushala Prasad

    2007-01-01

    This study describes the radioprotective ability of a hydrolysate prepared using an enzyme-acid hydrolysis method from the green mussel Perna viridis in terms of its ability to prevent radiation-induced damage in plasmid DNA, cell death, reactive oxygen species (ROS) formation, and DNA damage in mice lymphocytes. The mussel hydrolysate (MH) present during irradiation showed significant protection from gamma-radiation-induced strand breaks in plasmid DNA as evaluated by gel electrophoresis. Viability studies by trypan blue dye exclusion and MTT assay showed that preincubation of mice splenic lymphocytes with MH protected them from gamma-radiation-mediated killing. Moreover, the presence of MH during irradiation of isolated mice lymphocytes significantly decreased the DNA damage, as measured by comet assay. Measurement of intracellular ROS by dichlorofluorescein fluorescence revealed that the presence of MH effectively reduced the ROS generated in lymphocytes by both chemical method and gamma-irradiation. Prevention of DNA damage both in plasmid and lymphocytes and cell death in lymphocytes appears correlated with reduction of oxidatively generated free radicals. It is concluded that protection against radiation-induced cell death and DNA damage by MH was attributable to reduction of reactive free radical species generated by gamma-radiation. PMID:18197824

  4. Seasonality of bioaccumulation of trace organics and lysosomal integrity in green-lipped mussel Perna viridis.

    PubMed

    Fang, James K H; Wu, Rudolf S S; Zheng, Gene J; Lam, Paul K S; Shin, Paul K S

    2010-02-15

    Lysosomal integrity in mussels is widely used as a biomarker in coastal environments to demonstrate exposure to trace organic pollutants. However, few studies have determined the long-term influences of seasonal variations on the bioaccumulation of trace organics and subsequently altered response of lysosomal integrity in mussels. This study aimed to test three null hypotheses that (1) bioaccumulations of total polycyclic aromatic hydrocarbon (SigmaPAH) and (2) total polychlorinated biphenyl (SigmaPCB), and (3) lysosomal integrity as indicated by Neutral Red retention time (NRRT) in haemocytes, in the green-lipped mussel Perna viridis were not seasonally dependent. The tissue concentrations of SigmaPAH and SigmaPCB and haemocytic NRRT were determined in P. viridis in a metropolitan harbour, subtropical Hong Kong during the wet and dry seasons from 2004 to 2007. Additional information on temperature, salinity, dissolved oxygen and total ammonia nitrogen in seawater, and sediment levels of SigmaPAH and SigmaPCB, were extracted from published data and re-analyzed. Our results accepted all null hypotheses, based on the minimal seasonal influences of seawater temperature and salinity on all studied parameters, in which no significant differences between the wet and dry seasons were detected. The seasonal effect was likely outweighed by the greatly improved water quality and pollution abatement noted inside the harbour, with a gradual shift in mussel PAHs from a pyrolytic origin to a petrogenic origin. Spatially, the site east of the harbour was relatively unpolluted. The single use of NRRT in P. viridis explained 25% of the total variation of the integrated pollution patterns in seawater, sediments and mussels. The present study suggested that the dynamic change of trace organics could be reflected by the response on lysosomal integrity in P. viridis, which was recommended as a routine screening biomarker in monitoring of harbour water quality across seasons. PMID

  5. Optimizing deacetylation process for chitosan production from green mussel (perna viridis) shell

    NASA Astrophysics Data System (ADS)

    Danarto, Y. C.; Distantina, Sperisa

    2016-02-01

    The green mussel (perna viridis) shell waste could be utilized for chitosan production because it contained chitin. Chitin can be derived into chitosan through the deacetylation process. Chitosan is a polysaccharides polymer that is readily soluble in dilute acid solution and easily modified into other useful compounds. This research aimed to study the chitosan production from green mussel shells. This experiment had the following stages, deproteinization process aimed to eliminate the protein content using 1N NaOH solution, demineralization process aimed to remove minerals in green mussel shells as CaCO3 using 1 N HCl solution and decolorization process aimed to eliminate the color pigments and other impurities using ethanol solvent. All process above resulted chitin. Furthermore, chemical modification of chitin into chitosan by deacetylation process. This stage was very important because it greatly affected the chitosan properties. This research studied two different treatment for deacetylation process. The first treatment was the deacetylation process using concentrated NaOH solution (50% w), at high temperatures (90 - 100 °C) for 2 hours extraction, whilw the second treatment was deacetylation process using a low concentration of NaOH solution (15% w), at room temperature for 24 hours. The results showed that deproteinization, demineralization, and decolorizaton was capable of removing protein, mineral, and pigment. This experiment yield chitin 41.6 %wt. Chitosan yield from second treatment was 39.5%w and it was better than first treatment. Chitosan from first treatment had 79.8% degree of deacetylation and 16.5 kDa molecular weight. It was better than first treatment.

  6. A glycosylated byssal precursor protein from the green mussel Perna viridis with modified dopa side-chains.

    PubMed

    Ohkawa, Kousaku; Nishida, Ayako; Yamamoto, Hiroyuki; Waite, J Herbert

    2004-04-01

    Foot tissue of the green mussel Perna viridis contains a variety of byssal precursor proteins with the unusual redox-active amino acid, Dopa (-beta-3,4-dihydroxyphenyl-alpha-alanine). Eight proteins were detectable in acidic extracts of the Perna foot by a redox cycling assay with nitroblue tetrazolium. In one of these, however, P. viridis foot protein-1 (Pvfp-1), activity was not due to Dopa, but to another redox-active derivative. Based on specific colorimetric derivatization with Arnow's reagent, ninhydrin and phenylisothiocyanate (Edman), mass spectrometry, the redox-active derivative in Pvfp-1 is not consistent with any known modification. Another uncommon modification of Pvfp-1 involves O-glycosylation of threonine by mannose, glucose or fucose. As in previously characterized fp-1s, the primary sequence of the Pvfp-1 (apparent mass 89 kDa) has two consensus decapeptide motifs; one is APPKPX1TAX2K and the other is APPPAX1TAX2K, where P is Pro/Hyp, and X1 and X2 are difucosylated threonine and a redox sensitive derivative of tyrosine or Dopa, respectively. Of these two unusual residues, X2 is unique to Pvfp-1, whereas O-glycosylated Thr has been previously detected in freshwater mussel fp-1. The sequence homology of Pvfp-1 with the common structural motifs of the fp-1 protein family strongly suggests that the Pvfp-1 functions as the byssal coating (lacquer) protein. PMID:15203964

  7. An investigation of oxidative stress and antioxidant biomarkers during Greenshell mussel (Perna canaliculus) oocyte cryopreservation.

    PubMed

    Gale, Samantha L; Burritt, David J; Tervit, H Robin; Adams, Serean L; McGowan, Lindsay T

    2014-10-01

    Oxidative damage to proteins and lipids, the enzymatic and nonenzymatic antioxidants' response, and the fertilization and development capability of Perna canaliculus oocytes were investigated at critical treatment steps in a previously published controlled-rate cryopreservation protocol. The cryoprotectant (CPA) from this protocol comprises 10% ethylene glycol (v:v) and 0.2 M trehalose (wt/vol) final concentration. Critical treatment steps included (1) seawater control, (2) CPA addition, (3) CPA addition followed by cooling to -6 °C, (4) CPA addition and cooling to -10 °C, and (5) CPA addition and cooling to -35 °C and immersion in liquid nitrogen (LN). The percentage of fertilized oocytes was 53.8 ± 13.3% in the seawater control but was reduced to 26.0 ± 15.6% after -35 °C + LN treatment, whereas development to D-larvae was 21.0 ± 6.4% in the seawater control reduced to 4.8 ± 2.9% after cooling to -6 °C, and was zero at all the subsequent cooling steps. All oxidative damage biomarkers, protein carbonyls (PCs) and lipid hydroperoxides (LPs), and antioxidants, superoxide dismutase (SOD), catalase, glutathione peroxidase, percent reduced glutathione (%GSH), and total glutathione (defined as glutathione; reduced [GSH] plus glutathione disulphide; derived from two molecules of GSH [GSSG]) were measured over all treatments on unfertilized oocytes over a post-treatment recovery period of 0 to 240 minutes in seawater. An ANOVA showed that both treatment and post-treatment periods had significant effects on the concentrations of all biomarkers (P < 0.05). Protein carbonyls and LPs increased very little after CPA addition and cooling treatments, when compared with the seawater control, but large increases up to sixfold occurred between 0 and 240 minutes for the -35 °C + LN treatment. Concentrations of SOD, catalase, total glutathione, and %GSH at 0 minutes decreased by -31.2%, -26.9%, -21.9%, and -25.0%, respectively, between the seawater control and the -35

  8. Characterization of subpopulations and immune-related parameters of hemocytes in the green-lipped mussel Perna viridis.

    PubMed

    Wang, Youji; Hu, Menghong; Chiang, M W L; Shin, P K S; Cheung, S G

    2012-03-01

    The green-lipped mussel Perna viridis is distributed widely in the estuarine and coastal areas of the Indo-Pacific region and extensively cultured as an inexpensive protein source. Morphology and immunological activities of hemocytes of P. viridis were investigated using flow cytometry and light and electron microscopy. Three major types of hemocytes were identified in the hemolymph, including dense-granulocyte, semi-granulocyte (small and large size) and hyalinocyte. Other hemocytes, which occurred in low numbers, included granulocytes with different electron-dense/lucent granules and hemoblast-like cells. Based on flow cytometry, two subpopulations were identified. Granulocytes were larger cells, and the more abundant, containing numerous granules in the cytoplasm, and hyalinocytes were the smaller and less abundant with the fewest granules. Flow cytometry revealed that the granulocytes were more active in cell phagocytosis, contained the higher lysosomal content, and showed higher esterase activity and reactive oxygen species (ROS) generation compared with hyalinocytes. Immune functions assessed by the flow cytometry indicated that the granulocytes were the main hemocytes involved in the cellular defence in P. viridis. PMID:21982876

  9. Chronic hypoxia and low salinity impair anti-predatory responses of the green-lipped mussel Perna viridis.

    PubMed

    Wang, Youji; Hu, Menghong; Cheung, S G; Shin, P K S; Lu, Weiqun; Li, Jiale

    2012-06-01

    The effects of chronic hypoxia and low salinity on anti-predatory responses of the green-lipped mussel Perna viridis were investigated. Dissolved oxygen concentrations ranged from hypoxic to normoxic (1.5 ± 0.3 mg l(-1), 3.0 ± 0.3 mg l(-1) and 6.0 ± 0.3 mg l(-1)), and salinities were selected within the variation during the wet season in Hong Kong coastal waters (15‰, 20‰, 25‰ and 30‰). The dissolved oxygen and salinity significantly affected some anti-predatory responses of mussel, including byssus production, shell thickness and shell weight, and the adductor diameter was only significantly affected by salinity. Besides, interactive effects of dissolved oxygen and salinity on the byssus production and shell thickness were also observed. In hypoxic and low salinity conditions, P. viridis produced fewer byssal threads, thinner shell and adductor muscle, indicating that hypoxia and low salinity are severe environmental stressors for self-defence of mussel, and their interactive effects further increase the predation risk. PMID:22405812

  10. Monitoring trace metal contaminants in green mussel, Perna viridis from the coastal waters of Karnataka, southwest coast of India.

    PubMed

    Sasikumar, Geetha; Krishnakumar, P K; Bhat, G S

    2006-08-01

    The green mussel (Perna viridis) is widely distributed in the coastal waters of Asia and is used in mussel watch programmes for monitoring environmental contaminants throughout the region. Green mussels representing different size groups and habitats were sampled from their natural beds at 28 locations in the inshore waters of Karnataka (southwest coast of India) to analyze the tissue concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn. Tissue concentrations of Cr, Cu, Fe, and Pb were significantly higher in smaller mussels than in the larger size group. Significantly higher concentrations of Cr, Cu, Fe, Mn, and Ni were observed in mussels sampled from intertidal beds when compared to mussels from the subtidal beds. The sampling sites were categorized into industrial sites (IS), urban sites (US), and nonurban sites (NS) based on principal component analysis of metal concentrations in mussel. Spatial variations in tissue concentrations of all metals were observed except for Zn. Generally, the levels of toxic trace metals like Pb, Cd, Ni, and Cr in the whole tissue of P. viridis were within safe limits throughout the coast of Karnataka. However, relatively high concentrations of Cd, Cr, and Pb were observed in the whole tissue of green mussels collected from the industrial sites (IS), which may be derived from a variety of anthropogenic activities. PMID:16583254

  11. Predator-labeling effect on byssus production in marine mussels Perna viridis (L.) and Brachidontes variabilis (Krauss).

    PubMed

    Cheung, S G; Luk, K C; Shin, P K S

    2006-07-01

    Mussels Perna viridis and Brachidontes variabilis were exposed to chemical cues from the predatory crab Thalamita danae maintained on different diets, and byssal thread production of the mussels was studied. P. viridis produced the highest number as well as the thickest and longest byssal threads when they were exposed to crabs maintained on a diet of P. viridis as compared with those exposed to crabs maintained on a diet of the top shell Monodonta labio, the rock oyster Saccostrea cucullata, or crabs that were starved. For B. variabilis, results were similar, in that a diet containing B. variabilis elicited the greatest response as compared with other treatments. This indicates that the mussels were able to discriminate chemical cues released from predators maintained on different diets, and respond accordingly to the level of predation risk. By increasing the strength of byssal attachment as a defensive trait, the chance of being dislodged and consumed by crabs is reduced. As energy cost involved in the induction of an antipredatory response is considerable, this defensive trait seems to be an advantage to the mussels in enhancing efficiency. The short response time in byssal thread production allows the mussels to increase resistance against predation by crabs at the time when predation pressure is the highest in a tidal cycle. PMID:16718561

  12. Immunomodulation the marine green mussel Perna viridis exposed to sub-lethal concentrations of Cu and Hg.

    PubMed

    Thiagarajan, R; Gopalakrishnan, S; Thilagam, H

    2006-10-01

    Environmental pollution is a growing concern and, more importantly, pollution of the aquatic ecosystem is alarming. Marine pollution may be one of the reasons for disease incidence in marine organisms, which is caused due to adverse effects of pollutants on the immune system. Bivalves are commonly used as bio-indicators of marine pollution, and immunomodulation due to toxicants is one of the important bio-markers used. Perna viridis too have been used as a bio-indicator, but this study is, to our knowledge, a first report on immunomodulation produced by metals, in P. viridis. Animals were exposed to copper and mercury at their sub-lethal concentrations of 20 microg L(-1) and 10 microg L(-1), respectively. Immune parameters including phenoloxidase, reactive oxygen species generation, and phagocytosis were monitored. The study period was for 25 days (chronic long-term exposure) and objectives established whether metals produced immunomodulation and to understand the effects of long-term exposure on immunomodulation. Results showed that both metals adversely affected immune parameters studied and, interestingly, there appears to be some level of recovery (depuration) from the toxic effects of metals. PMID:16823522

  13. Toxic effects of lead on biochemical and histological alterations in green mussel (Perna viridis) induced by environmentally relevant concentrations.

    PubMed

    Hariharan, G; Purvaja, R; Ramesh, R

    2014-01-01

    Acute and chronic toxicity tests were conducted on green mussel (Perna viridis) to determine the adverse effects of lead (Pb). Exposure of organisms to acute toxicity test for 96 h and lethal concentration (LC(50)) was the endpoint of the test. Acute toxicity for 96-h LC(50) and 95% confidence intervals of P. viridis was 2.62 ± 0.12 (2.62-3.24) mg/L Pb. Chronic toxicity tests revealed that survival of exposed organisms decreased with elevated exposure concentrations. No-observed-effect concentration (NOEC) and lowest-observed-effect concentration (LOEC) were calculated based on survival of test organisms. Results of this study demonstrated an increase in toxicity in test organisms with rise in exposure time and concentration. In this study, histology and biochemical enzymes, namely, catalase, reduced glutathione, glutathione S-transferase, and lipid peroxides, were correlated with chronic value and survival endpoints of P. viridis after chronic exposure to Pb. Biochemical and histological responses to different concentrations of Pb were assessed and significant differences were observed between control and increasing exposure concentrations. Biomarker studies in internal organs confirmed that the observed changes are due to adverse effects of Pb. This assessment of toxicity was the first step to determining the seawater quality criteria for marine organisms. PMID:24588225

  14. Occurrence of polychlorinated biphenyls and polybrominated diphenyl ethers in green mussels (Perna viridis) from Singapore, Southeast Asia.

    PubMed

    Bayen, Stéphane; Thomas, Gareth Owen; Lee, Hian Kee; Obbard, Jeffrey Philip

    2003-10-01

    The green mussel, Perna viridis, was used in this study to measure levels of polychlorinated biphenyls (PCBs) and, for the first time, polybrominated diphenyl ethers (PBDE) in the marine environment. Samples were collected from eight different locations in the coastal waters of Singapore between April and May 2002. Forty-one PCB and 21 PBDE congeners were quantified by gas chromatography-mass spectrometry and were all positively detected in the mussel tissues. Total concentrations in green mussel tissues ranged from 6.1 to 82 ng/g and 2.0 to 38 ng/g on a dry-weight basis for PCBs and PBDEs, respectively. Such levels reflect the ubiquity of these persistent organic pollutants in a tropical marine environment. Principal component analysis was applied to the PCB data and revealed similarities in the congener composition of mussel tissues to that of the commercial PCB mixture, Aroclor 1254. The PBDE levels, to date, were approximately one order of magnitude greater than the upper concentrations reported for blue mussel (Mytilus edulis) tissues in Europe. At some sampling sites, the congener composition of PBDEs in P. viridis tissues indicated recent exposure to a commercial pentabrominated flame retardant. PMID:14552008

  15. Mate locating and access behaviour of the parasitic pea crab, Nepinnotheres novaezelandiae, an important parasite of the mussel Perna canaliculus

    PubMed Central

    Trottier, Oliver; Jeffs, Andrew G.

    2015-01-01

    Pea crabs are globally ubiquitous symbionts in the marine environment that cause serious economic impact in the aquaculture production of several major bivalve species. However, little is known about their host-parasite interactions, especially the mating behaviour of these parasites that could prove useful for controlling their infestation in aquaculture. In this study, the mate location behaviour of male New Zealand pea crabs, Nepinnotheres novaezelandiae (Filhol, 1885), was observed when dwelling in its preferred host, the commercially important green-lipped mussel, Perna canaliculus. Given the cryptic behaviour of the male crabs, a novel trapping system was developed to determine whether male crabs would exit their mussel hosts in response to an upstream female crab. The presence of receptive female crabs placed upstream successfully attracted 60% of male crabs from their host over 24 h. Observations of the nocturnal mate-finding behaviour of male crabs were made in darkness using infrared video recordings. Males spent on average 49 min on empty hosts and never left a mussel containing a female conspecific once found, spending 200 min on average to gain entry to the mussel. Male crabs were often observed stroking the mantle edge of the mussel whilst attempting to gain entry, successfully increasing mussel valve gape during entry from 3.7 to 5.5 mm. A pheromone-based mate location system is likely used by this crab to greatly reduce the risks associated with the location of females. PMID:25786327

  16. Tissue-specific toxicological effects of cadmium in green mussels (Perna viridis): nuclear magnetic resonance-based metabolomics study.

    PubMed

    Wu, Huifeng; Wang, Wen-Xiong

    2011-04-01

    Toxicity tests for metals have traditionally focused on selected biomarkers to characterize the biological stress induced by metals in marine organisms. Here nuclear magnetic resonance (NMR)-based metabolomics, a system biology tool, was applied to the marine green mussel, Perna viridis, to investigate the toxicological effects of Cd in both digestive gland and adductor muscle tissues. After Cd exposure for either two or four weeks, there was no significant metabolic change in the mussels exposed to Cd at 2 µg/L. At 20 µg/L, there were major metabolite changes related to amino acids, osmolytes, and energy metabolites. Digestive gland tissue was more sensitive to Cd than adductor muscle tissue. The adductor muscle tissue showed elevated levels of glutamine, glutamate, and lactate, and reduced levels of branched chain amino acids, aspartate, phenylalanine, and tyrosine. Overall, four weeks of Cd exposure produced neurotoxicity and metabolic disturbances and disturbed osmoregulation. These results suggest that the adductor muscle tissue of mussels may be a suitable supplemental biomarker for exposure to toxicants. In addition, the results demonstrate that (1) H-NMR-based metabolomic analysis can provide a systematic view of the toxicological effects of metals on mussels, suggesting that it might be employed to investigate the toxicological effects of other marine pollutants. PMID:21184531

  17. Efficacy of marinades against Listeria monocytogenes cells in suspension or associated with green shell mussels (Perna canaliculus).

    PubMed Central

    Bremer, P J; Osborne, C M

    1995-01-01

    In order to determine the listericidal efficacies of three marinades used in the production of marinated green shell mussels (Perna canaliculus), decimal reduction times (D values) were determined for a mixture of seven strains of Listeria monocytogenes exposed to marinades in the presence and absence of mussels. With an acetic acid (1.5%, wt/vol) marinade, calculated D values in the presence and absence of mussels were 77.3 and 33.3 h, respectively. Likewise, for an acetic acid (0.75%)-lactic acid (0.75%) marinade and an acetic acid (1.5%)-Glucono Delta-Lactone (0.2%)-based marinade, the D values in the presence and absence of mussels were 125.5 and 26.9 h and 86.3 and 19.3 h, respectively. Various increases in decimal reduction times in the presence of mussels indicated that there was no simple relationship between the listericidal natures of these marinades and the presence of mussels. This result suggests that difficulties may occur in trying to relate acid inhibition studies carried out in model broth systems to "real food" systems. PMID:7747968

  18. Screening for antioxidant and detoxification responses in Perna canaliculus Gmelin exposed to an antifouling bioactive intended for use in aquaculture.

    PubMed

    Cahill, Patrick Louis; Burritt, David; Heasman, Kevin; Jeffs, Andrew; Kuhajek, Jeanne

    2013-10-01

    Polygodial is a drimane sesquiterpene dialdehyde derived from certain terrestrial plant species that potently inhibits ascidian metamorphosis, and thus has potential for controlling fouling ascidians in bivalve aquaculture. The current study examined the effects of polygodial on a range of biochemical biomarkers of oxidative stress and detoxification effort in the gills of adult Perna canaliculus Gmelin. Despite high statistical power and the success of positive controls, the antioxidant enzymes glutathione reductase (GR), glutathione peroxidase (GPOX), catalase (CAT), and superoxide dismutase (SOD); thiol status, as measured by total glutathione (GSH-t), glutathione disulphide (GSSG), and GSH-t/GSSG ratio; end products of oxidative damage, lipid hydroperoxides (LHPO) and protein carbonyls; and detoxification pathways, represented by GSH-t and glutathione S-transferase (GST), were unaffected in the gills of adult P. canaliculus exposed to polygodial at 0.1 or 1 × the 99% effective dose in fouling ascidians (IC₉₉). Similarly, GR levels, thiol status, and detoxification activities were unaffected in mussels exposed to polygodial at 10 × the IC₉₉, although GPOX, CAT, and SOD activities increased. However, the increases were small relative to positive controls, no corresponding oxidative damage was detected, and this concentration greatly exceeds effective doses required to inhibit fouling ascidians in aquaculture. These findings compliment a previous study that established the insensitivity to polygodial of P. canaliculus growth, condition, and mitochondrial functioning, providing additional support for the suitability of polygodial for use as an antifouling agent in bivalve aquaculture. PMID:23830117

  19. Uptake and elimination of brevetoxin in the invasive green mussel, Perna viridis, during natural Karenia brevis blooms in southwest Florida.

    PubMed

    McFarland, Katherine; Jean, Fred; Soudant, Philippe; Volety, Aswani K

    2015-04-01

    Perna viridis is a recently introduced species to US coastal waters and have vigorously spread throughout the southeastern seaboard since their invasion. Little information regarding their response to local environmental factors has been reported including responses to the local HAB species, Karenia brevis. This study monitored the tissue toxin concentration of brevetoxins in P. viridis from existing populations throughout two consecutive natural K. brevis blooms. The results showed P. viridis to rapidly accumulate PbTx upon exposure to the bloom, far exceeding the peak tissue concentrations of oysters, Crassostrea virginica, sampled during the same period, 57,653 ± 15,937 and 33,462 ± 10,391 ng g(-1) PbTx-3 equivalent, respectively. Further, P. viridis retained high PbTx concentrations in their tissues post bloom remaining above the regulatory limit for human consumption for 4-5 months, significantly longer than the depuration time of 2-8 weeks for native oyster and clam species. In the second year, the bloom persisted at high cell concentrations resulting in prolonged exposure and higher PbTx tissue concentrations indicating increased bioaccumulation in green mussels. While this species is not currently harvested for human consumption, the threat for post bloom trophic transfer could pose negative impacts on other important fisheries and higher food web implications. PMID:25681577

  20. Chlorination-induced genotoxicity in the mussel Perna viridis: assessment by single cell gel electrophoresis (comet) assay.

    PubMed

    Chavan, Pooja; Kumar, Rajesh; Kirubagaran, Ramalingam; Venugopalan, Vayalam P

    2016-08-01

    Mussels are important fouling organisms in the cooling water systems of coastal power plants. Continuous low-dose chlorination (CLDC) is being practiced as an effective method to control mussel biofouling in power plant cooling water systems. CLDC effectively controls mussel fouling by discouraging larval settlement rather than by killing the larvae or adults. Mussels are an integral part of the natural benthic community in the receiving water body where the coolant water is discharged. Hence, from a toxicological point of view, they can serve as both target and non-target organisms. Previous researchers have indicated that chlorine residual, rather than elevated temperature, can be the major stress factor in the effluents released from coastal power plants. However, very little data are available on the sub-lethal effects of low level chlorination on representative benthic fauna. In this study, we used native and transplanted mussels (Perna viridis) to study lethal and sub-lethal effects of chlorination in the cooling water circuit of an operating power plant. Experiments involving comet assay suggested that CLDC can cause DNA damage in treated mussels. However, activation of DNA repair appeared to get initiated after the accrued damage reached a threshold. The results indicate that, at chlorine residual levels observed at the discharge point, exposure to chlorinated effluents is unlikely to cause significant genetic damage to mussels in the recipient water body. PMID:27155389

  1. Mate locating and access behaviour of the parasitic pea crab, Nepinnotheres novaezelandiae, an important parasite of the mussel Perna canaliculus.

    PubMed

    Trottier, Oliver; Jeffs, Andrew G

    2015-01-01

    Pea crabs are globally ubiquitous symbionts in the marine environment that cause serious economic impact in the aquaculture production of several major bivalve species. However, little is known about their host-parasite interactions, especially the mating behaviour of these parasites that could prove useful for controlling their infestation in aquaculture. In this study, the mate location behaviour of male New Zealand pea crabs, Nepinnotheres novaezelandiae (Filhol, 1885), was observed when dwelling in its preferred host, the commercially important green-lipped mussel, Perna canaliculus. Given the cryptic behaviour of the male crabs, a novel trapping system was developed to determine whether male crabs would exit their mussel hosts in response to an upstream female crab. The presence of receptive female crabs placed upstream successfully attracted 60% of male crabs from their host over 24 h. Observations of the nocturnal mate-finding behaviour of male crabs were made in darkness using infrared video recordings. Males spent on average 49 min on empty hosts and never left a mussel containing a female conspecific once found, spending 200 min on average to gain entry to the mussel. Male crabs were often observed stroking the mantle edge of the mussel whilst attempting to gain entry, successfully increasing mussel valve gape during entry from 3.7 to 5.5 mm. A pheromone-based mate location system is likely used by this crab to greatly reduce the risks associated with the location of females. PMID:25786327

  2. Levels of heavy metals in green-lipped mussel Perna veridis (Linnaeus) from Muar Estuary, Johore, Malaysia.

    PubMed

    Kamaruzzaman, B Y; Ong, M C; Zaleha, K; Shahbudin, S

    2008-09-15

    Muscle and feather in tissue of 40 juveniles and 40 adult green-lipped mussel Perna veridis (L.) collected from Muar Estuary, Johor were analyzed for copper (Cu), cadmium (Cd), lead (Pb) and zinc (Zn) concentration using a fast and sensitive Inductively Coupled Plasma Mass Spectrometer (ICP-MS). In this study, the average concentration of Cu was 8.96 microg g(-1) dry weights, Cd with 0.58 microg g(-1) dry weight, Pb averaging 2.28 microg g(-1) dry weights and Zn averaged to 86.73 microg g(-1) dry weight. The highest accumulation of metal studied was found in feather sample compared to the muscle. The positive relationship of Cu, Cd, Pb and Zn with P. virdis length suggesting that the accumulation of these metals were formed in the mussel. In all cases, metal levels found were lower than the guideline of international standards of reference and the examined bivalve were not associated with enhanced metal content in their tissues and were safe within the limits for human consumption. PMID:19137835

  3. Establishment of the green mussel, Perna viridis (Linnaeus 1758) (Mollusca: Mytilidae) on the West Coast of Florida

    USGS Publications Warehouse

    Benson, A.J.; Marelli, D.C.; Frischer, M.E.; Danforth, J.M.; Williams, J.D.

    2001-01-01

    In 1999, the green mussel, Perna viridis, was first observed in Tampa Bay, Florida. This was the first reported occurrence of this Indo-Pacific marine bivalve in North America. The mussels found in Tampa Bay were confirmed to be P. viridis based on both morphological and genetic characteristics. Since the initial discovery, surveys in Tampa Bay and on the west coast of Florida have documented the growth, recruitment, and range expansion of P. viridis. From November 1999 to July 2000, the mean shell length of a Tampa Bay population increased from 49.0 mm to 94.1 mm, an increase of 97%. Populations of P. viridis are successfully reproducing in Tampa Bay. Recruitment was observed on sampling plates in May and continued through July 2000. The full extent of mussel colonization is not clear, but mussels were found outside Tampa Bay in St. Petersburg, Florida, south to Venice. Based on these studies it is evident that P. viridis has successfully invaded Tampa Bay and the west coast of Florida. The long-term impact of P. viridis on native communities off the west coast of Florida cannot be predicted at this time.

  4. Effects of metals on {alpha}-amylase activity in the digestive gland of the green mussel, Perna viridis L.

    SciTech Connect

    Yan, T.; Teo, L.H.; Sin, Y.M.

    1996-04-01

    A number of digestive enzymes in the green mussel, Perna viridis L., have been reported, and {alpha}-amylase is believed to have a higher activity than the others. Small plankton, on which the green mussel feeds, may supply plenty of starch and glycogen. They may be an important source of nutrients for the green mussel and the ability of the latter to make good use of them depends mainly on the activities of amylase. The effect of heavy metals on amylase activity is also important as the ability of the mussel`s digestive gland to accumulate these metals is well known. High concentrations of heavy metals, especially lead, have been observed in the water around Singapore. The in vitro inhibition of some metals on the activities of digestive enzymes from the green mussel has been observed, but kinetic properties of the inhibition and the in vivo inhibition of the heavy metals on digestive enzymes are little understood. In the present study, in vitro inhibition of four metals (Pb, Cd, Zn and Hg) on the activity of {alpha}-amylase from the digestive gland of the green mussel will be compared. Their effects on the K{sub M} and V{sub max} values of {alpha}-amylase will also be compared. Finally, lead is either added to the food or water, to see how it affects the activity of {alpha}-amylase and how this effect acts in combination with starvation. 12 refs., 3 figs., 3 tabs.

  5. Isolation, purification and characterization of beta-1,3-glucan binding protein from the plasma of marine mussel Perna viridis.

    PubMed

    Jayaraj, S S; Thiagarajan, R; Arumugam, M; Mullainadhan, P

    2008-06-01

    A beta-1,3-glucan binding protein (betaGBP) specific for laminarin (a beta-1,3-glucan) was detected for the first time in a mollusc, Perna viridis. betaGBP was isolated and purified from the plasma using laminarin precipitation and affinity chromatography on laminarin-Sepharose 6B, respectively. It agglutinated bakers yeast, bacteria, and erythrocytes and enhanced prophenoloxidase (proPO) activity of the plasma in a dose-dependent manner. The purified betaGBP appeared as a single band in native-PAGE and the purity was conformed by HPLC. The protein has a molecular weight estimate of 510kDa as determined by SDS-PAGE and in isoelectric focusing the purified betaGBP was focused as a single band at pI 5.3. betaGBP was found to possess inherent serine protease activity but lacked beta-1,3-glucanase activity and all these results suggest that plasma betaGBP of P. viridis functions as a recognition molecule for beta-1,3-glucan on the surface of microbial cell walls. This recognition and binding lead to the activation of the prophenoloxidase cascade mediated by the inherent serine protease activity of betaGBP. Presence of agglutinating activity and serine protease activity shows that betaGBP is a bifunctional protein. The findings are discussed in light of the importance of this protein in the innate immune response of P. viridis, and they implicate evolutionary link with similar proteins found in other invertebrates. PMID:18420422

  6. Crystalline style and tissue redistribution in Perna viridis as indicators of Cu and Pb bioavailabilities and contamination in coastal waters.

    PubMed

    Yap, C K; Ismail, A; Cheng, W H; Tan, S G

    2006-03-01

    The concentrations of Cu, Pb, and Zn in the crystalline style (CS) and in the remaining soft tissues (ST) of the green-lipped mussel Perna viridis from 10 geographical sites along the coastal waters off peninsular Malaysia were determined. The CS, compared with the remaining ST, accumulated higher levels of Cu in both contaminated and uncontaminated samples, indicating that the style has a higher affinity for the essential Cu to bind with metallothioneins. The similar pattern of Cu accumulation in the different ST of mussels collected from clean and Cu-contaminated sites indicated that the detoxification capacity of the metallothioneins had not been overloaded. For Pb, higher levels of the metal in the CS than in the remaining ST were found only in mussels collected from a contaminated site at Kg. Pasir Puteh. This indicated a tissue redistribution of Pb due to its binding to metallothioneins for Pb detoxification and the potential of the CS as an indicator organ of Pb bioavailability and contamination. For Zn, the above two phenomena were not found since no obvious patterns were observed (lower levels of Zn in the CS than in the remaining ST) in contaminated and uncontaminated samples due to the mechanism of partial regulation. Generally, all the different STs studied (foot, mantle, gonad, CS, gill, muscle, and byssus) are good biomonitoring tissues for Cu and Pb bioavailabilities and contamination. Among these organs, the CS was found to be the best organ for biomonitoring Cu. The present data also suggest the use of the tissue redistribution of Pb in P. viridis as an indicator of Pb bioavailability and contamination in coastal waters. PMID:16406592

  7. Seasonal variation of oxidative biomarkers in gills and digestive gland of green-lipped mussel Perna viridis from Arabian Sea

    NASA Astrophysics Data System (ADS)

    Verlecar, X. N.; Jena, K. B.; Chainy, G. B. N.

    2008-03-01

    Investigations on seasonal variation in oxidative stress biomarkers were carried out on the natural population of green-lipped mussel Perna viridis collected from Bambolim beach area of Goa. Oxidative stress indices such as lipid peroxidation (LPX), hydrogen peroxide (H 2O 2), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione transferase (GST), glutathione reductase (GR), reduced glutathione (GSH) and ascorbic acid (ASA) were measured in gills and digestive gland of P. viridis during February, May, August and November. The present study reveals two important aspects regarding the antioxidant defence status of tissues of P. viridis. Firstly, antioxidant capacity of tissues of P. viridis exhibits seasonal variation. Secondly, various components of antioxidant capacity such as oxidative stress markers, levels of antioxidant enzymes and small antioxidant molecules vary differently in tissues with respect to different seasons. Although the oxidative stress status of gills and digestive gland of P. viridis expressed in terms of LPX and H 2O 2 was the lowest in February, its level was maximal in gills and digestive gland during May and November, respectively. While activities of SOD and GPX of tissues of P. viridis were found to be low in August, activities of CAT and GR were recorded to be low in February. GST activity in gills although remained high in February, in digestive gland elevated values were recorded in August and November. A seasonal variation in the levels of small antioxidant molecules was also noticed. Among non enzymatic antioxidants ASA content of tissues was maximal in May and August in comparison to February and November, but GSH remained high in November. It therefore appears that environmental factors may play a crucial role in regulating the oxidative stress capacity of tissues of P. viridis.

  8. Thermal constraints for range expansion of the invasive green mussel, Perna viridis, in the southeastern United States.

    PubMed

    Urian, Alyson G; Hatle, John D; Gilg, Matthew R

    2011-01-01

    Cold temperatures are thought to be among the most important determining factors of geographic distribution for tropical and sub-tropical marine invertebrates. The Asian green mussel, Perna viridis, has been introduced into coastal waters of Florida where its current distribution is hypothesized to be limited by low temperatures during winter. Lethal and sub-lethal effects (heat shock protein/Hsp70 expression) of cold water and air temperatures were analyzed in two size classes of P. viridis from Florida in an effort to determine the effects of current and forecasted temperatures on the potential for range expansion. Mussels were exposed to water temperatures of 14, 10, 7 and 3°C for up to 30 days, or to air temperatures of 14, 7, 0 and -10°C for periods of 2 hr. Mortality was significantly increased at all water and air temperatures ≤14°C. No differences in mortality rates were observed between small (15-45 mm) and large (75-105 mm) size classes except after exposure to 7°C air, in which small mussels had higher mortality. Significant increases in Hsp70 expression were observed after a 2-hour exposure to 10°C water, but Hsp70 expression was not significantly increased at any temperatures in which mortality was not also significant. The temperature threshold for survival in this population appears to be between 10 and 14°C, suggesting that under current conditions P. viridis may already be at the northern edge of its potential range in the United States. If water temperatures increase with global climate change, northerly flowing currents may permit range expansion as temperatures allow. PMID:20853420

  9. Coating Proteins: Structure and Cross-Linking in fp-1 from the Green Shell Mussel Perna canaliculus†‡

    PubMed Central

    Zhao, Hua; Waite, J. Herbert

    2007-01-01

    The protein family known as fp-1 provides mussel byssus with a protective outer coating and has drawn much attention for its water resistant bioadhesive properties in vitro. A new fp-l isolated from the green shell mussel Perna canaliculus (pcfp-1) reveals a composition dominated by only four amino acids: 3,4-dihydroxyphenyl-L-alanine (dopa), lysine, proline, and valine at ~20 mol % each. SDS–PAGE and MALDI-TOF mass spectrometry detected size variants at 48 and 52 kDa in preparations of purified Pcfp-1. The N-terminal sequence enabled construction of oligonucleotide primers for PCR and RACE-derived cDNAs from which the complete sequence of four variants was deduced. pcfp-1 deviates from all known homologues in other mussels in several notable respects: its mass is half, most of its sequence is represented by 75 tandem repeats of a tetrapeptide, i.e., PY*VK, in which Y* is dopa, prolines are not hydroxylated, and thiolate cysteines are clustered in homologous sequences at both the amino and carboxy termini. Amino acids in the repeat sequence show a striking resemblance to proline-rich cell wall proteins with tandemly repeated PPVYK pentapeptides [Hong, J. C., Nagao, R. T., and Key, J. L. (1987) J. Biol. Chem. 262, 8367–8376]. Cysteine plays a key role in cross-linking pcfp-1 by forming adducts with dopaquinone. Significant 5-S-cysteinyldopa and smaller amounts of 2-S-cysteinyldopa were detected in hydrolysates of the byssal threads of P. canaliculus. The cross-links could also be formed by oxidation of pcfp-1 in vitro using mushroom tyrosinase. Cysteinyldopa cross-links were present in trace amounts only in the byssus of other mussel species. PMID:16313194

  10. Linking trace element variations with macronutrients and major cations in marine mussels Mytilus edulis and Perna viridis.

    PubMed

    Liu, Fengjie; Wang, Wen-Xiong

    2015-09-01

    Marine mussels have long been used as biomonitors of contamination of trace elements, but little is known about whether variation in tissue trace elements is significantly associated with those of macronutrients and major cations. The authors examined the variability of macronutrients and major cations and their potential relationships with bioaccumulation of trace elements. The authors analyzed the concentrations of macronutrients (C, N, P, S), major cations (Na, Mg, K, Ca), and trace elements (Al, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Pb) in the whole soft tissues of marine mussels Mytilus edulis and Perna viridis collected globally from 21 sites. The results showed that 12% to 84% of the variances in the trace elements was associated with major cations, and the tissue concentration of major cations such as Na and Mg in mussels was a good proxy for ambient seawater concentrations of the major cations. Specifically, bioaccumulation of most of the trace elements was significantly associated with major cations, and the relationships of major cations with trace cations and trace oxyanions were totally opposite. Furthermore, 14% to 69% of the variances in the trace elements were significantly associated with macronutrients. Notably, more than half of the variance in the tissue concentrations of As, Cd, V, Ba, and Pb was explained by the variance in macronutrients in one or both species. Because the tissue macronutrient concentrations were strongly associated with animal growth and reproduction, the observed coupling relationships indicated that these biological processes strongly influenced the bioaccumulation of some trace elements. The present study indicated that simultaneous quantification of macronutrients and major cations with trace elements can improve the interpretation of biomonitoring data. PMID:25900884

  11. Thermal Constraints for Range Expansion of the Invasive Green Mussel, Perna viridis, in the Southeastern United States

    PubMed Central

    URIAN, ALYSON G.; HATLE, JOHN D.; GILG, MATTHEW R.

    2013-01-01

    Cold temperatures are thought to be among the most important determining factors of geographic distribution for tropical and sub-tropical marine invertebrates. The Asian green mussel, Perna viridis, has been introduced into coastal waters of Florida where its current distribution is hypothesized to be limited by low temperatures during winter. Lethal and sub-lethal effects (heat shock protein/Hsp70 expression) of cold water and air temperatures were analyzed in two size classes of P. viridis from Florida in an effort to determine the effects of current and forecasted temperatures on the potential for range expansion. Mussels were exposed to water temperatures of 14, 10, 7 and 3°C for up to 30 days, or to air temperatures of 14, 7, 0 and –10°C for periods of 2 hr. Mortality was significantly increased at all water and air temperatures ≤ 14°C. No differences in mortality rates were observed between small (15–45 mm) and large (75–105 mm) size classes except after exposure to 7°C air, in which small mussels had higher mortality. Significant increases in Hsp70 expression were observed after a 2-hour exposure to 10°C water, but Hsp70 expression was not significantly increased at any temperatures in which mortality was not also significant. The temperature threshold for survival in this population appears to be between 10 and 14°C, suggesting that under current conditions P. viridis may already be at the northern edge of its potential range in the United States. If water temperatures increase with global climate change, northerly flowing currents may permit range expansion as temperatures allow. PMID:20853420

  12. Screening for negative effects of candidate ascidian antifoulant compounds on a target aquaculture species, Perna canaliculus Gmelin.

    PubMed

    Cahill, Patrick Louis; Heasman, Kevin; Hickey, Anthony; Mountfort, Douglas; Jeffs, Andrew; Kuhajek, Jeannie

    2013-01-01

    The natural chemical compounds radicicol, polygodial and ubiquinone-10 (Q10) have previously been identified as inhibitors of metamorphosis in ascidian larvae. Accordingly, they have potential as a specific remedy for the costly problem of fouling ascidians in bivalve aquaculture. In this study, these compounds were screened for their effects on the physiological health of an aquaculture species, the green-lipped mussel, Perna canaliculus Gmelin, at or above the 99% effective dose (IC(99)) in ascidians. Three physiological biomarkers of mussel health were screened: growth (increases in shell height and wet weight), condition (condition index) and mitochondrial respirational function (Complex I-mediated respiration, Complex II-mediated respiration, maximum uncoupled respiration, leak respiration, respiratory control ratios and phosphorylation system control ratios). While polygodial and Q10 had no effect on mussel growth or the condition index, radicicol retarded growth and decreased the condition index. Mitochondrial respirational function was unaffected by radicicol and polygodial. Conversely, Q10 enhanced Complex I-mediated respiration, highlighting the fundamental role of this compound in the electron transport system. The present study suggests that polygodial and Q10 do not negatively affect the physiological health of P. canaliculus at the IC(99) in ascidians, while radicicol is toxic. Moreover, Q10 is of benefit in biomedical settings as a cellular antioxidant and therefore may also benefit P. canaliculus. Accordingly, polygodial and Q10 should be progressed to the next stage of testing where possible negative effects on bivalves will be further explored, followed by development of application techniques and testing in a laboratory and aquaculture setting. PMID:23194394

  13. Variations of 210Po activity in mussel (Perna viridis) of Samut Sakhon and its contribution to dose assessment

    NASA Astrophysics Data System (ADS)

    Porntepkasemsan, B.; Srisuksawad, K.; Kulsawat, W.

    2015-05-01

    The activities of 210Po and its effective dose in green mussel (Perna viridis) collected from a mussel farming area in Samut Sakhon province during the period of 20122013 are presented. Several parameters including maximum shell length and the physiological performance of mussels using condition index and physical properties of seawater (pH, salinity, conductivity, TDS, DO and cation-anion elements) were measured. Each individual mussel was measured for its maximum shell length which was adopted as size class. The activity concentration of 210Po was determined spectroscopically through its 5.30 MeV alpha particle emission, using 209Po as an internal tracer. The 210Po activity concentration in mussels was found to vary between 1.044 and 6.951 Bq/kg wet weight. The 210Po concentration was higher in smaller-sized (≤35 mm) and lower in larger ones (40-70 mm). This confirmed that larger mussels have lower 210Po activities on a weight basis. The 210Po body burden (activity per mussel) ranged from 1.035 to 17.183 mBq. Contrary to the 210Po concentrations, results of the body burden revealed the lower activities in smaller-sized mussels (≤35 mm) and the higher in larger-sized ones (40-70 mm). The type of fluctuations observed with 210Po concentrations were interpreted as a seasonal effect. Total annual effective 210Po dose due to mussel consumption was calculated to be in the range of 3.081 to 16.401 pSv. Based on the international guideline, the average dose calculated due to 210Po in mussels of Samut Sakhon would not pose any significant radiological impact on human health and the mussels are considered to be safe for consumption.

  14. P-glycoprotein expression in Perna viridis after exposure to Prorocentrum lima, a dinoflagellate producing DSP toxins.

    PubMed

    Huang, Lu; Wang, Jie; Chen, Wen-Chang; Li, Hong-Ye; Liu, Jie-Sheng; Tao Jiang; Yang, Wei-Dong

    2014-08-01

    Bivalves naturally exposed to toxic algae have mechanisms to prevent from harmful effects of diarrhetic shellfish poisoning (DSP) toxins. However, quite few studies have examined the mechanisms associated, and the information currently available is still insufficient. Multixenobiotic resistance (MXR) is ubiquitous in aquatic invertebrates and plays an important role in defense against xenobiotics. Here, to explore the roles of P-glycoprotein (P-gp) in the DSP toxins resistance in shellfish, complete cDNA of P-gp gene in the mussel Perna viridis was cloned and analyzed. The accumulation of okadaic acid (OA), a main component of DSP toxins, MXR activity and expression of P-gp in gills of P. viridis were detected after exposure to Prorocentrum lima, a dinoflagellate producing DSP toxins in the presence or absence of P-gp inhibitors PGP-4008, verapamil (VER) and cyclosporin A (CsA). The mussel P. viridis P-gp closely matches MDR/P-gp/ABCB protein from various organisms, having a typical sequence organization as full transporters from the ABCB family. After exposure to P. lima, OA accumulation, MXR activity and P-gp expression significantly increased in gills of P. viridis. The addition of P-gp-specific inhibitors PGP-4008 and VER decreased MXR activity induced by P. lima, but had no effect on the OA accumulation in gills of P. viridis. However, CsA, a broad-spectrum inhibitor of ABC transporter not only decreased MXR activity, but also increased OA accumulation in gills of P. viridis. Together with the ubiquitous presence of other ABC transporters such as MRP/ABCC in bivalves and potential compensatory mechanism in P-gp and MRP-mediated resistance, we speculated that besides P-gp, other ABC transporters, especially MRP might be involved in the resistance mechanisms to DSP toxins. PMID:24811006

  15. Assimilation of cadmium, chromium, and zinc by the green mussel Perna viridis and the clam Ruditapes philippinarum

    SciTech Connect

    Chong, K.; Wang, W.X.

    2000-06-01

    The green mussel Perna viridis and the clam Ruditapes philippinarum have been frequently used as biomonitors of coastal contamination in subtropical and tropical waters, yet the physiological processes controlling metal uptake in these bivalves are unknown. Assimilation efficiency (AE) is an important physiological parameter quantifying metal bioavailability from ingested food. The authors determined the AEs of Cd, CR, and Zn in these bivalves feeding on five species of phytoplankton and one natural section. The influences of the cytoplasmic distribution of metals in the algal cells and the digestive physiology of bivalves on metal AEs were also examined. Among the three metals, Zn was generally assimilated at the highest efficiency, i.e., 21 to 36% in the mussels and 29 to 59% in the clams. Cr was the least assimilated metal, with AEs being 10 to 16% in the mussels and 11 to 24% in the clams. The AEs of Cd and Zn in the clams were 1.8 to 4.7 and 1.1 to 1.9 times higher, respectively, than the AEs in the mussels. Assimilation efficiencies of Cr were, however, comparable between the mussels and the clams. A positive significant relationship between the metal AE and the percent of metals in the algal cytoplasm was found only for Cd in the clams, suggesting that Cd fractionation in the algal cells influenced its assimilation. No significant relationship, however, was found for other metals in both bivalves. A significant relationship between Cr-assimilation efficiency and gut passage time (GPT) was documented in the mussels, indicating a higher assimilation when Cr was retained longer in the gut. There was also significant correlation of metal AEs among the three metals, which were probably subjected to the same digestive pathway in the bivalves. Their study demonstrated that both the green mussels and the clams were able to accumulate metals from ingested food source, and food quality appeared to have different effects on metal assimilation in different bivalve

  16. Mercury depuration effectiveness on green mussel (Perna viridis L.) and blood cockle (Anadara granosa L.) from Jakarta Bay using ozone, chitosan and hydrodynamic technique

    NASA Astrophysics Data System (ADS)

    Widiah Ningrum, Endar; Duryadi Solihin, Dedy; Butet, Nurlisa A.

    2016-01-01

    Depuration has been used to eliminate microorganism and toxic chemical contaminants in bivalve. However, scientific research still needs to discover the effectiveness of depuration. This research aimed at assessing the best depuration effectiveness in decreasing mercury (Hg) concentration level in two species of bivalves, green mussel (Perna viridis L.) and blood cockle (Anadara granosa L.). The depuration treatments applied 1.5 ppm ozon, 0.5 ppm chitosan, hydrodynamic technique (1.3 m/s), combination between hydrodynamic-ozon, hydrodynamic-chitosan and ozon-chitosan. The experiment were conducted in mini aquaria for 60 minutes. Mercury concentration was measured in 10 g dry weight of green mussel (4.05±0.020 ppm) and blood cockle (3.27 ± 0.666 ppm). The result showed that mercury depuration were highly effective by combination of ozone-chitosan in green mussel (96.51%) and 1.5 ppm ozone in blood cockle (87.06%).

  17. Biomonitoring of heavy metals and trace organics using the intertidal mussel Perna viridis in Hong Kong coastal waters.

    PubMed

    Liu, J H; Kueh, C S W

    2005-01-01

    This paper presents the results of a 6-year (1998-2003) survey of trace toxics in the intertidal mussel Perna viridis conducted by the Hong Kong Environmental Protection Department. Concentrations of heavy metals and trace organics were measured in the soft bodies of P. viridis collected from five sites in Hong Kong waters, i.e. Wu Kai Sha (Tolo Harbour), Ma Wan (Northwest), Tsim Sha Tsui (Victoria Harbour), Tai Tam (Hong Kong South) and Lamma Island (Southern Waters) in order to establish the spatial patterns of contaminants in mussels. Among the metals analysed, Cd showed a significant concentration gradient in Hong Kong waters. The levels of Cd in P. viridis were significantly higher at Ma Wan as compared to the other sites studied. Ma Wan also had relatively higher concentrations of Pb. Mn concentrations were particularly prominent at Wu Kai Sha. Significantly higher concentrations of Hg and Cu were recorded at Tai Tam and Tsim Sha Tsui. Tai Tam and Wu Kai Sha had higher levels of V; whereas higher Ni concentrations were recorded at Lamma Island and Tai Tam. No clear spatial patterns for Al, As, Cr, Fe and Zn were observed. Higher concentrations of PAHs in P. viridis were observed around urban centres impacted by sewage discharges (e.g. Tsim Sha Tsui); whereas higher PCB levels were found not only in Tsim Sha Tsui but also in less urbanised areas such as Lamma Island and Tai Tam, suggesting that these may be due to non-sewage related inputs. The study also shows that Northwest and Southern waters are subject to a higher degree of DDT pollution compared with other sites. Of the 17 dioxin compounds analysed, positive data were mostly recorded for two compounds which are of low toxicity (i.e. OCDD and 1,2,3,4,6,7,8-HpCDD) whereas the most toxic congeners (i.e. 2,3,7,8-TCDD and 1,2,3,7,8-PeCDD) were not detected in the 6 years of monitoring. In general, the levels of OCDD in P. viridis were found to be higher in Tai Tam and Lamma Island in Southern Waters of Hong

  18. Non-Lethal Heat Shock of the Asian Green Mussel, Perna viridis, Promotes Hsp70 Synthesis, Induces Thermotolerance and Protects Against Vibrio Infection

    PubMed Central

    Aleng, Nor Afiqah; Sung, Yeong Yik; MacRae, Thomas H.; Abd Wahid, Mohd Effendy

    2015-01-01

    Mild heat stress promotes thermotolerance and protection against several different stresses in aquatic animals, consequences correlated with the accumulation of heat shock protein 70 (Hsp70). The purpose of this study was to determine if non-lethal heat shock (NLHS) of the Asian green mussel, Perna viridis, an aquatic species of commercial value, promoted the production of Hsp70 and enhanced its resistance to stresses. Initially, the LT50 and LHT for P. viridis were determined to be 42°C and 44°C, respectively, with no heat shock induced death of mussels at 40°C or less. Immunoprobing of western blots revealed augmentation of constitutive (PvHsp70-1) and inducible (PvHsp70-2) Hsp70 in tissue from adductor muscle, foot, gill and mantel of P. viridis exposed to 38°C for 30 min followed by 6 h recovery, NLHS conditions for this organism. Characterization by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that PvHsp70-1 and PvHsp70-2 respectively corresponded most closely to Hsp70 from P. viridis and Mytilus galloprovincialis. Priming of adult mussels with NLHS promoted thermotolerance and increased resistance to V. alginolyticus. The induction of Hsp70 in parallel with enhanced thermotolerance and improved protection against V. alginolyticus, suggests Hsp70 functions in P. viridis as a molecular chaperone and as a stimulator of the immune system. PMID:26288319

  19. Toxicities and tolerances of Cd, Cu, Pb and Zn in a primary producer (Isochrysis galbana) and in a primary consumer (Perna viridis).

    PubMed

    Yap, C K; Ismail, A; Omar, H; Tan, S G

    2004-02-01

    Studies on toxicities and tolerances of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in the brown alga Isochrysis galbana and in the green-lipped mussel Perna viridis were conducted by short-term bioassays using endpoints growth production and mortality, respectively. The 5-day EC(50) and 24-h LC(50) of these heavy metals were determined in the brown alga and mussel, respectively. The EC(50) values calculated for the alga were 0.74 mg/l for Cd, 0.91 mg/l for Cu, 1.40 mg/l for Pb and 0.60 mg/l for Zn. The LC(50) values for the mussels were 1.53 mg/l for Cd, 0.25 mg/l for Cu, 4.12 mg/l for Pb and 3.20 mg/l for Zn. These LC(50) values were within the concentration ranges as reported by other authors who used P. viridis as the test organism. Based on these EC(50) and LC(50) values, the alga was most sensitive to Zn, followed by Cd, Cu and Pb while the mussel was most sensitive to Cu, followed by Cd, Zn and Pb. Differences in the trophic levels, metal handling strategies, biology and ecology of the primary producer (brown alga) and the primary consumer (mussel) are believed to be the plausible causes for the different toxicities and tolerances of the metals studied. PMID:14680893

  20. Influences of ammonia-nitrogen and dissolved oxygen on lysosomal integrity in green-lipped mussel Perna viridis: laboratory evaluation and field validation in Victoria Harbour, Hong Kong.

    PubMed

    Fang, J K H; Wu, R S S; Chan, A K Y; Yip, C K M; Shin, P K S

    2008-12-01

    Lysosomal integrity in mussels has been applied as a biomarker to detect the pollution of trace organics and metals in the natural environments. However, few studies have examined the effects of water quality on the response of lysosomal integrity, in particular total ammonia-nitrogen (TAN) and dissolved oxygen (DO). This study demonstrated that high level of TAN (2.0mg/l) and low DO (2.5mg O(2)/l) could significantly reduce the lysosomal integrity in green-lipped mussel Perna viridis, respectively by 33% and 38%, whereas the mussel lysosomal integrity decreased by 70% in the combined treatment of TAN and low DO under laboratory conditions after one week. The mussel lysosomal integrity of all treatment groups could return to the control level after a three week recovery period. In the field validation in Victoria Harbour, Hong Kong during an one-year study period, lysosomal integrity in P. viridis identified the cleanest site east to the harbour, where the lowest TAN and highest DO concentrations were found. While lysosomal integrity in mussels seemed not affected by seasonal changes, approximately 40% of the variation of this biomarker could be attributable to the changes in TAN and DO in seawater. In conclusion, the response of the mussel lysosomal integrity can be confounded by both TAN and DO prevailing in the natural environments and thus caution must be exercised in relating the observed changes in lysosomal integrity to any specific pollutant in coastal water quality monitoring studies. PMID:18789457

  1. Isoform-specific responses of metallothioneins in a marine pollution biomonitor, the green-lipped mussel Perna viridis, towards different stress stimulations.

    PubMed

    Leung, Priscilla T Y; Park, T J; Wang, Yu; Che, C M; Leung, Kenneth M Y

    2014-08-01

    Metallothioneins (MTs) are commonly used as biomarker for metal pollution assessment in marine ecosystems. Using integrated genomic and proteomic analyses, this study characterized two types of MT isoform in the digestive gland of a common biomonitor, the green-lipped mussel Perna viridis, towards the challenges of a metal (cadmium; Cd) and a non-metal oxidant (hydrogen peroxide; H2 O2 ) respectively. The two isoforms differed in their deduced protein sequences, with 73 amino acids for MT10-I and 72 for MT10-II (a novel type), but both consisted of a high percentage (27.4 to 29.2%) of cysteine. Two-dimensional gel and Western blot showed that the MT proteins were present in multiple isoform spots, and they were further validated to be MT10-I and MT10-II using MS analysis coupled with unrestricted modifications searching. Expression of mRNA revealed that MT10-I responded promptly to Cd but had a lagged induction to H2 O2 treatments, while MT10-II was exclusively induced by Cd treatment over the course of exposure. Expression of the MT proteins also showed a delayed response to H2 O2 , compared to Cd treatments. This study uncovered the potential different functional roles of various MTs isoforms in P. viridis and thus advances the resolution of using MTs as biomarkers in future applications. PMID:24838682

  2. Non-Lethal Heat Shock of the Asian Green Mussel, Perna viridis, Promotes Hsp70 Synthesis, Induces Thermotolerance and Protects Against Vibrio Infection.

    PubMed

    Aleng, Nor Afiqah; Sung, Yeong Yik; MacRae, Thomas H; Abd Wahid, Mohd Effendy

    2015-01-01

    Mild heat stress promotes thermotolerance and protection against several different stresses in aquatic animals, consequences correlated with the accumulation of heat shock protein 70 (Hsp70). The purpose of this study was to determine if non-lethal heat shock (NLHS) of the Asian green mussel, Perna viridis, an aquatic species of commercial value, promoted the production of Hsp70 and enhanced its resistance to stresses. Initially, the LT50 and LHT for P. viridis were determined to be 42°C and 44°C, respectively, with no heat shock induced death of mussels at 40°C or less. Immunoprobing of western blots revealed augmentation of constitutive (PvHsp70-1) and inducible (PvHsp70-2) Hsp70 in tissue from adductor muscle, foot, gill and mantel of P. viridis exposed to 38°C for 30 min followed by 6 h recovery, NLHS conditions for this organism. Characterization by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that PvHsp70-1 and PvHsp70-2 respectively corresponded most closely to Hsp70 from P. viridis and Mytilus galloprovincialis. Priming of adult mussels with NLHS promoted thermotolerance and increased resistance to V. alginolyticus. The induction of Hsp70 in parallel with enhanced thermotolerance and improved protection against V. alginolyticus, suggests Hsp70 functions in P. viridis as a molecular chaperone and as a stimulator of the immune system. PMID:26288319

  3. Concentrations of heavy metals (Cu, Cd, Zn and Ni) and PAHs in Perna viridis collected from seaport and non-seaport waters in the Straits of Johore.

    PubMed

    Yap, C K; Shahbazi, A; Zakaria, M P

    2012-12-01

    In this study, the ranges of pollutants found in the soft tissues of Perna viridis collected from Kg. Masai and Kg. Sg. Melayu, both located in the Straits of Johore, were 0.85-1.58 μg/g dry weight (dw) for Cd, 5.52-12.2 μg/g dw for Cu, 5.66-8.93 μg/g dw for Ni and 63.4-72.3 μg/g dw for Zn, and 36.4-244 ng/g dry weight for ∑PAHs. Significantly (p < 0.05) higher concentrations of Cd, Cu, Ni, Zn and ∑PAHs in the mussels were found in the water of a seaport site at Kg. Masai than a non-seaport site at Kg. Sg. Melayu population. The ratios of low molecular weight/high molecular weight hydrocarbons (2.94-3.42) and fluoranthene/pyrene (0.43-0.45) in mussels from both sites indicated the origin of the PAHs to be mainly petrogenic. This study has demonstrated the utility of using the soft tissues of P. viridis as a biomonitor of PAH contamination and bioavailability in the coastal waters of Peninsular Malaysia. PMID:23052577

  4. Sub-lethal effects of cadmium and copper on RNA/DNA ratio and energy reserves in the green-lipped mussel Perna viridis.

    PubMed

    Yeung, Jamius W Y; Zhou, Guang-Jie; Leung, Kenneth M Y

    2016-10-01

    This study aims to test if RNA/DNA ratio and various energy reserve parameters (i.e., glycogen, lipid, protein content and total energy reserves) are sensitive biomarkers for indicating stresses induced by metal contaminants in the green-lipped mussel Perna viridis, a common organism for biomonitoring in Southeast Asia. This study was, therefore, designed to examine the effects of cadmium (Cd) and copper (Cu) on these potential biomarkers in two major energy storage tissues, adductor muscle (AM) and hepatopancreas (HP), of P. viridis after sub-lethal exposure to either metal for 10 days. The results showed that neither Cd nor Cu treatments affected the RNA/DNA ratio, glycogen and protein contents in AM and HP. As the most sensitive biomarker in P. viridis, the total lipid content in both AM and HP was significantly decreased in the treatment of 5μg Cu/L and 0.01-0.1μgCd/L, respectively. However, soft-tissue body burdens of Cu or Cd did not significantly correlate with each of the four biomarkers regardless of the tissue type. In addition, AM generally stored more glycogen than HP, whereas HP stored more lipids than AM. We proposed that multiple biomarkers may be employed as an integrated diagnostic tool for monitoring the health condition of the mussels. PMID:27262215

  5. Persistency of highly toxic coplanar PCBs in aquatic ecosystems: uptake and release kinetics of coplanar PCBs in green-lipped mussels (Perna viridis Linnaeus).

    PubMed

    Kannan, N; Tanabe, S; Tatsukawa, R; Phillips, D J

    1989-01-01

    The bioaccumulation potential of three highly toxic coplanar PCB isomers [3,3',4,4'-tetrachlorobiphenyl (T(4)CB); 3,3',4,4',5-pentachlorobiphenyl (P(5)CB); and 3,3',4,4',5,5'-hexachlorobiphenyl (H(6)CB)] was investigated using green-lipped mussels (Perna viridis Linnaeus) as a bioindicator, through a transplantation experiment at two locations in Hong Kong waters. By contrast to the relatively rapid uptake and release of many other PCB isomers, the non-ortho chlorine substituted coplanar PCB congeners exhibited slow uptake and clearance. The kinetic parameters of coplanar PCBs based on lipid weight-related data, and the degree of bioaccumulation based on the proportion of coplanar PCBs in total PCBs in mussels, clearly indicate that coplanar PCBs are highly bioaccumulative in lower organisms. On the assumption that mussels are unlikely to be particularly unusual with respect to their bioaccumulation of coplanar PCBs, it appears most likely that these highly toxic and persistent PCB congeners are concentrated by all aquatic organisms, and may reach higher consumers (including humans) in quantities of toxicological concern. PMID:15092492

  6. Impact of marine pollution in green mussel Perna viridis from four coastal sites in Karachi, Pakistan, North Arabian Sea: histopathological observations.

    PubMed

    Khan, Muhammad Iftikhar; Ayub, Zarrien; Siddiqui, Ghazala

    2015-04-01

    Pathological changes are regarded as a standard technique to monitor the effects of pollutants in marine animals. Histopathological examination of the population of green mussel Perna viridis (L.) from four sites in Pakistan, namely, Manora Channel, Rehri Creek, Sandspit Backwaters and Bhanbore was conducted. The first three sites are on the Karachi coast, whereas the fourth one, Bhanbore is situated outside Karachi, and is considered to be less polluted. Two types of parasites, Rickettsia-like organisms and metacestode were found in the mussels studied. In the present study, we observed various pathological lesions, such as inflammatory responses, granulocytomas, lipofuscin pigments, vacuolation in the digestive gland and gonads, lamellar fusion and dilated hemolymphatic sinus in the gills of P. viridis. These observations indicate the extent of environmental pollution in the studied areas. Although, Bhanbore is considered to be relatively less polluted compared to other three sites, the present results have revealed that the waters of Bhanbore are also polluted as evidenced by the pathological changes observed in the mussels collected from there. PMID:26011983

  7. Patterns of rapd markers and heavy metal concentrations in Perna viridis (L.), collected from metal-contaminated and uncontaminated coastal waters: are they correlated with each other?

    PubMed

    Yap, C K; Chua, B H; Teh, C H; Tan, S G; Ismail, A

    2007-05-01

    Genetic variation due to heavy metal contamination has always been an interesting topic of study. Because of the numerous contaminants being found in coastal and intertidal waters, there is always much discussion and argument as to which contaminant(s) caused the variations in the genetic structures of biomonitors. This study used a Single Primer Amplification Reaction (SPAR) technique namely Random Amplified Polymorphic DNA (RAPD) to determine the genetic diversity of the populations of the green-lipped mussel Perna viridis collected from a metal-contaminated site at Kg. Pasir Puteh and those from four relatively' uncontaminated sites (reference sites). Heavy metal levels (Cd, Cu, Pb and Zn) were also measured in the soft tissues and byssus of the mussels from all the sites. Cluster analyses employing UPGMA done based on the RAPD makers grouped the populations into two major clusters; the Bagan Tiang, Pantai Lido, Pontian and Kg. Pasir Puteh populations were in one cluster, while the Sg. Belungkor population clustered by itself. This indicated that the genetic diversity based on bands resulting from the use of all four RAPD primers on P. viridis did not indicate its potential use as a biomarker of heavy metal pollution in coastal waters. However, based on a correlation analysis between a particular metal and a band resulting from a specific RAPD primer revealed some significant (P < 0.01) correlations between the primers and the heavy metal concentrations in the byssus and soft tissues. Thus, the correlation between a particular metal and the bands resulting from the use of a specific RAPD primer on P. viridis could be used as biomonitoring tool of heavy metal pollution. PMID:17633561

  8. Allozyme polymorphisms and heavy metal levels in the green-lipped mussel Perna viridis (Linnaeus) collected from contaminated and uncontaminated sites in Malaysia.

    PubMed

    Yap, C K; Tan, S G; Ismail, A; Omar, H

    2004-03-01

    It has been widely reported that heavy metal contamination in coastal waters can modify the allozyme profiles of marine organisms. Previous studies have recorded elevated metal concentrations in sediments and mussel tissues off Peninsular Malaysia. In the present study, horizontal starch gel electrophoresis was carried out to estimate the levels of allelic variation of the green-lipped mussel, Perna viridis, collected from one contaminated and three relatively uncontaminated sites off Peninsular Malaysia. Fourteen polymorphic loci were observed. In addition, the concentrations of cadmium, copper, lead, mercury and zinc were determined in the sediments and in the soft tissues of the mussels. Mussels from contaminated site, evidenced by high metal pollution indices (MPI) of the sediment and the mussel tissues, showed the highest percentage of polymorphic loci (78.6%), while those collected from the uncontaminated sites had lower MPI of the sediment and mussel tissue, and exhibited lower percentages of polymorphic loci (35.7-57.1%). The population from the contaminated site showed the highest excess of heterozygosity (0.289) when compared to that of the populations from the three uncontaminated sites (0.108-0.149). Allozyme frequencies at the phosphoglucomutase (PGM; E.C. 2.7.5.1) locus also differed between the contaminated and uncontaminated populations. Previous studies have shown that exposure to heavy metals can select or counter-select for particular alleles at this locus. The present results suggest that allozyme polymorphism in P. viridis is a potential biomonitoring tool for heavy metal contamination but further validation is required. PMID:14664863

  9. DNA adduct formation and DNA strand breaks in green-lipped mussels (Perna viridis) exposed to benzo[a]pyrene: dose- and time-dependent relationships.

    PubMed

    Ching, E W; Siu, W H; Lam, P K; Xu, L; Zhang, Y; Richardson, B J; Wu, R S

    2001-07-01

    Green-lipped mussels, Perna viridis, were exposed to 0, 0.3, 3 and 30 micrograms l-1 (nominal concentrations) B[a]P under laboratory conditions over a period of 24 days. Mussels were collected on day 0, 1, 3, 6, 12, 18 and 24, and the levels of DNA adducts and DNA strand breaks in their hepatopancreas tissues monitored. Mussels exposed to 0.3 and 3 micrograms l-1 B[a]P showed marked increases in strand breaks after 1 day of exposure. DNA strand break levels in these mussels remained high and significantly different from the control values until day 3 for the 0.3 microgram l-1 treatment group, and day 6 for the 3 micrograms l-1 treatment group. This was followed by a gradual reduction in strand breaks. After 12 days, the levels of both groups had returned to the same level as that of the control. No increase in DNA strand breaks was observable in mussels exposed to 30 micrograms l-1 B[a]P in the first 12 days of exposure, but a significant increase was observed from day 12 to day 24. Increasing B[a]P concentrations resulted in elevated DNA adduct levels after 3-6 days of exposure, but this pattern of dose-related increase disappeared after 12 days. These results indicate that a better understanding of the complex interactions between exposure levels and durations is crucially important before DNA adduct levels and DNA strand breaks in P. viridis can be used as effective biomarkers for monitoring genotoxicants in marine waters. PMID:11488241

  10. Application of the comet and micronucleus assays to the detection of B[a]P genotoxicity in haemocytes of the green-lipped mussel (Perna viridis).

    PubMed

    Siu, W H L; Cao, J; Jack, R W; Wu, R S S; Richardson, B J; Xu, L; Lam, P K S

    2004-03-10

    Green-lipped mussels (Perna viridis) were exposed to water-borne benzo[a]pyrene (B[a]P) at nominal concentrations of 0, 0.3, 3 and 30 microg l(-1) for up to 12 days, and both the relative levels of DNA strand breaks (assessed using an alkaline comet assay) and the proportion of micronucleus (MN) formation were monitored in mussel haemocytes at days 0, 1, 3, 6 and 12. The results of the comet assay indicated that an increase in the proportion of strand breaks occurred generally with increasing B[a]P concentration, but a significant decrease in the levels of DNA damage was observed after exposure for 12 days at all concentrations tested, suggesting that the patterns of changes in the levels of DNA strand breakage can be explained by the threshold dependent DNA repair theory. Moreover, the relatively slow development and recovery of the DNA damage response in mussel haemocytes in comparison with previous findings utilizing P. viridis hepatopancreas suggests that the response of DNA alteration upon exposure to B[a]P may be tissue-specific in this species. Monitoring the frequency of micronucleus development in mussel haemocytes indicated both dose- and time-response relationships within the exposure period. Furthermore, the levels of DNA strand breakage correlated well with the levels of micronucleus induction, suggesting a possible cause and effect relationship between the two damage types. We suggest that DNA strand breakage and micronucleus formation in mussel haemocytes can potentially be used as convenient biomarkers of exposure to genotoxicants in the marine environment. PMID:15168946

  11. Sublethal effect of silver and chromium in the green mussel Perna viridis with reference to alterations in oxygen uptake, filtration rate and membrane bound ATPase system as biomarkers.

    PubMed

    Vijayavel, K; Gopalakrishnan, S; Balasubramanian, M P

    2007-10-01

    Perna viridis is an ideal animal for studying the impairment caused by the effects of heavy metals that are often detected in coastal areas. Preliminary bioassay tests revealed that the lethal (LC(100)), median lethal (LC(50)) and sublethal (LC(0)) concentration of silver and chromium to P. viridis were 6.5, 4.0, 2.0 mg l(-1) and 4.5, 2.5, 1.0 mg l(-1), respectively. Toxic effect of silver and chromium was evaluated in the green mussel P. viridis, with reference to oxygen consumption, filtration rate and ATPase system in laboratory experiments. These parameters were selected as the end point of sublethal stress. Oxygen consumption and filtration rates were calculated as a measure of decline in the dissolved oxygen level and algal concentration (feed) in the aquaria water, respectively. Silver and chromium affects both oxygen consumption and filtration rate significantly (P<0.01) at 96 h when compared to control. The activity of ATPases system in the gills, hepatopancreas, ovary and muscle of mussels were inhibited by silver and chromium indicating that metals exerted significant toxic effect. The inhibition of Na(+)K(+) ATPase, Ca(2+) ATPase and Mg(2+) ATPase in the mussels were significant (P<0.05) for silver and highly significant (P<0.01) for chromium, which indicates that chromium was more toxic to mussels when compared to silver. The assessment of oxygen consumption, filtration and ATPases system can thus be used as a valid biomarker in aquatic ecotoxicology studies. PMID:17585996

  12. Can the shell of the green-lipped mussel Perna viridis from the west coast of Peninsular Malaysia be a potential biomonitoring material for Cd, Pb and Zn?

    NASA Astrophysics Data System (ADS)

    Yap, C. K.; Ismail, A.; Tan, S. G.; Abdul Rahim, I.

    2003-07-01

    The distributions of Cd, Pb and Zn in the total soft tissues and total shells of the green-lipped mussel Perna viridis were studied in field collected samples as well as from laboratory experimental samples. The results showed that Cd, Pb and Zn were readily accumulated in the whole shells. In mussels sampled from 12 locations along the west coast of Peninsular Malaysia, the ratios of the shell metals to the soft tissue metals were different at each sampling site. Nevertheless, the Cd and Pb levels in the shells were always higher than those in the soft tissues, while the Zn level was higher in the soft tissues than in the shells. In comparison with soft tissues, the degrees of variability for Pb and Cd concentrations in the shells were lower. The lower degrees of variability and significant ( P<0.05) correlation coefficients of Cd and Pb within the shells support the use of the mussel shell as a suitable biomonitoring material for the two metals rather than the soft tissue since this indicated that there is more precision (lower CV) in the determination of metal concentrations in the shell than in the soft tissue. Experimental work showed that the pattern of depuration in the shell was not similar to that of the soft tissue although their patterns of accumulation were similar. This indicated that the depuration of heavy metals in the shell was not affected by the physiological conditions of the mussels. Although Zn could be regulated by the soft tissue, the incorporated Cd, Pb and Zn remained in the shell matrices. The present results support the use of the total shell of P. viridis as a potential biomonitoring material for long-term contamination of Cd, Pb and Zn.

  13. Immune toxicity of TiO₂ under hypoxia in the green-lipped mussel Perna viridis based on flow cytometric analysis of hemocyte parameters.

    PubMed

    Wang, Youji; Hu, Menghong; Li, Qiongzhen; Li, Jiale; Lin, Daohui; Lu, Weiqun

    2014-02-01

    The combined effects of DO and TiO2 (mixed rutile/anatase phase, 7/3) on immune responses in Perna viridis were examined. Mussels were exposed to six combinations of oxygen levels (hypoxia: 1.5 mg O2l(-1), normoxia: 6.0 mg O2 l(-1)) and TiO2 concentrations (0, 2.5 mg l(-1) and 10 mg l(-1)) for 216 h. Mussels were sampled after 24h, 48h, 120 h and 216 h, and immune parameters of hemocytes, including mortality, phagocytosis, non-specific esterase, ROS production, lysosomal content and total hemocyte count were investigated using flow cytometric assay. Hemocyte mortality was higher under hypoxia than normoxia, and increased with TiO2 concentrations, but no interaction was found between DO and TiO2. Phagocytosis was reduced under hypoxia and decreased with TiO2 exposure, and the interactive effect between time and TiO2 was observed. The percentage of hemocytes showing non-specific esterase activity was lower under hypoxia, and decreased as TiO2 concentration increased with the significant interactive effect of DO and TiO2. ROS production and lysosomal content were lower under hypoxia and reduced as concentration of TiO2 increased, and interactive effect of DO and TiO2 on ROS was evident. THC was significantly affected by the interactive effect between TiO2 and DO, with higher values under normoxia in the presence of TiO2. The present study demonstrated that immune functions of P. viridis were influenced by both nano-TiO2 and hypoxia with some synergistic effects between the two stressors. This implies that DO has to be considered in the evaluation of the toxicity of nano-materials to bivalves. PMID:24189102

  14. Toxic effects of male Perna viridis gonad exposed to BaP, DDT and their mixture: A metabolomic and proteomic study of the underlying mechanism.

    PubMed

    Song, Qinqin; Zheng, Pengfei; Qiu, Liguo; Jiang, Xiu; Zhao, Hongwei; Zhou, Hailong; Han, Qian; Diao, Xiaoping

    2016-01-01

    Benzo(a)pyrene and dichlorodiphenyltrichloroethane are typical persistent organic pollutants, and also the widespread environmental estrogens with known toxicity towards green mussels Perna viridis. In this study, the toxicological effects of BaP and DDT and their mixture were assessed in green mussel gonads using proteomic and metabolomic approaches. Metabolomics by NMR spectroscopy revealed that BaP did not show obvious metabolite changes in the gonad of male green mussel. DDT mainly caused some disturbance of osmotic regulation and energy metabolism by changing BCAAs, alanine, threonine, arginine, etc., unknown metabolite (3.53 ppm), glycine, homarine and ATP at different levels. However, the mixture of BaP and DDT mainly caused some disturbance in osmotic regulation and energy metabolism by differentially altering branched chain amino acids, glutamate, alanine, arginine, unknown metabolite (3.53 ppm), glycine, 4-aminobutyrate, dimethylglycine, homarine and ATP. The results suggest that DDT alone may cause most of metabolites changes in the mixture exposed male mussel gonad, and the results also show that the male P. viridis gonad was more sensitive to DDT than BaP exposures. Proteomic study showed that BaP, DDT and their mixture may have different modes of action. Proteomic responses revealed that BaP induced signal transduction, oxidative stress, spermatogenesis, etc. in the male green mussel gonad; whereas DDT exposure altered proteins that were associated with signal transduction, oxidative stress, cytoskeleton and cell structure, cellular organization, energy metabolism, etc. However, the mixture of BaP and DDT affected proteins related to cytoskeleton and cell structure, oxidative stress, cellular organization, etc. This research demonstrated that metabolomic and proteomic approaches could better elucidate the underlying mechanism of environmental pollutants gonad toxicity. PMID:26546779

  15. Seasonal variation in antioxidative responses and acetylcholinesterase activity in Perna viridis in eastern oceanic and western estuarine waters of Hong Kong

    NASA Astrophysics Data System (ADS)

    Lau, P. S.; Wong, H. L.; Garrigues, Ph.

    2004-10-01

    A year-round study was conducted to assess the seasonal variations and potential influence of the riverine discharge from the Pearl River on biomarker responses in Hong Kong waters. A suite of biomarkers including antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), the lipid peroxidation product malondialdehyde (MDA), a Phase II detoxification enzyme glutathione-S-transferase (GST) and the neural transmitter enzyme acetylcholinesterase (AChE) in the green mussel, Perna viridis, were monitored from three coastal sites, Port Shelter, Tung Chung and Tai O, stretching from the east to the west of Hong Kong. Despite of the seasonal variations, the total protein profiles suggested that mussels from the three sites had a growth cycle that was in phase with each other. This implied that intrinsic variation between sites due to a different phase of growth was minimal. Seasonal variations of the biomarker responses in the mussels were found to be significant (Tukey multiple comparison test, p<0.05) with a summer minimum and winter maximum. On top of seasonal variations, the western site, Tai O, was further subjected to the reduced salinity effect of the Pearl River discharge in the summer wet season. This was demonstrated by the significant July minimum in all the biomarker responses at Tai O in relation to the extreme low salinity of 8‰. Mussels from the western site also revealed a higher oxidative stress than those from the eastern side throughout the year (Tukey multiple comparison test, p<0.05), which could be caused by chemical pollutants from the Pearl River discharge. ANOVAs of the year-round dataset suggested that size was a minor factor in affecting the biomarker responses. Gill tissues of the mussels were more advantageous for biomarker studies or monitoring because their protein levels were less sensitive to seasonal variations and they yielded a higher protein normalized biomarker response than the whole body tissues. This increases their

  16. Mussels as bioindicators of PCB pollution: a case study on uptake and release of PCB isomers and congeners in green-lipped mussels (Perna viridis) in Hong Kong waters.

    PubMed

    Tanabe, S; Tatsukawa, R; Phillips, D J

    1987-01-01

    The uptake and release of PCB isomers and congeners were examined in green-lipped mussels (Perna viridis) through a transplantation experiment in two locations in Hong Kong waters. Rapid rates of uptake and release of relatively less lipophilic lower-chlorinated PCBs were observed in the mussels, indicating that the primary mechanism of bioaccumulation of lipophilic pollutants in P. viridis complies with the concept of equilibrium partitioning. Thus, data for contaminant concentrations are most appropriately based upon lipid weights of samples when using mussels as bioindicators of aquatic PCB pollution. Considering the kinetic parameters of PCBs based on lipid weight-related data, it is concluded that P. viridis has the ability to respond rapidly to changes in ambient levels of PCBs. This is significant in determining the usefulness and limitations of mussels as bioindicators for monitoring programmes investigating aquatic pollution by PCBs. PMID:15092720

  17. Correlations between speciation of Cd, Cu, Pb And Zn in sediment and their concentrations in total soft tissue of green-lipped mussel Perna viridis from the west coast of Peninsular Malaysia.

    PubMed

    Yap, C K; Ismail, A; Tan, S G; Omar, H

    2002-04-01

    Total concentrations and speciation of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in surface sediment samples were correlated with the respective metal measured in the total soft tissue of the green-lipped mussel Perna viridis, collected from water off the west coast of Peninsular Malaysia. The aim of this study is to relate the possible differences in the accumulation patterns of the heavy metals in P. viridis to those in the surface sediment. The sequential extraction technique was employed to fractionate the sediment into 'freely leachable and exchangeable' (EFLE), 'acid-reducible,' 'oxidisable-organic' and 'resistant' fractions. The results showed that significant (P<.05) correlations were observed between Cd in P. viridis and Cd in the sediment (EFLE fraction and total Cd), Cu in P viridis and Cu in the sediment (EFLE and 'acid-reducible' fractions and total Cu) and Pb in P viridis and Pb in the sediment ('oxidisable-organic' fraction and total Pb). No significant correlation (P > .05) was found between Zn in P viridis and all the sediment geochemical fractions of Zn and total Zn in the sediment. This indicated that Zn was possibly regulated from the soft tissue of P. viridis. The present results supported the use of P viridis as a suitable biomonitoring agent for Cd, Cu and Pb. PMID:12046948

  18. Can the byssus of green-lipped mussel Perna viridis (Linnaeus) from the west coast of Peninsular Malaysia be a biomonitoring organ for Cd, Pb and Zn? Field and laboratory studies.

    PubMed

    Yap, C K; Ismail, A; Tan, S G

    2003-07-01

    Concentrations of cadmium (Cd), lead (Pb) and zinc (Zn) in total soft tissues (ST) and byssus (BYS) of the green-lipped mussel Perna viridis from 11 different geographical locations off the west coast of Peninsular Malaysia were determined. The metal concentrations distributed between the BYS and ST were compared. The results of this study indicated that higher levels of Cd (1.31 microg/g), Pb (38.49 microg/g) and Zn (206.52 microg/g) were accumulated in the BYS than in the total ST (Cd: 0.29 microg/g; Pb: 8.27 microg/g; Zn: 102.6 microg/g). Semi-static and short period controlled laboratory experiments were also conducted for the accumulation and depuration of Cd, Pb and Zn in the total ST and BYS of P. viridis. The ratios (BYS/ST) for Pb and Cd from the laboratory experiments showed that the total ST accumulated more metals than the BYS. Therefore, these laboratory results disagreed with those found for the field samples. However, the laboratory results for the Zn ratio (BYS/ST) agreed with those of the field samples. It was evident that when compared to the ST, the BYS was a more sensitive biomonitoring organ for Zn while it could be a complementary organ for Cd and Pb in the total ST. Since total ST of P. viridis had been reported to have regulative mechanism for Zn, its BYS can be used as a biomonitoring organ for the identification of coastal areas exposed to Zn pollution. PMID:12705949

  19. Potential impacts of blooms of the toxic dinoflagellate Karenia brevis on the growth, survival and juvenile recruitment of the non-native green mussel Perna viridis in southeastern United States.

    PubMed

    McFarland, Katherine; Jean, Fred; Thébault, Julien; Volety, Aswani K

    2016-01-01

    Red tide blooms formed by Karenia brevis are frequent along the Gulf coast of Florida and it is unclear what tolerance the green mussel Perna viridis, a recently introduced species to coastal waters, has toward these events. Established populations of P. viridis were monitored along the coastal waters of Estero Bay, Florida before, during and following two consecutive red tide blooms to assess the potential effects on growth, survival and juvenile recruitment. Upon onset of the bloom, growth rates fell from 6 to 10 mm month(-1) (March 2011-November 2011) to less than 3 mm month(-1). In the succeeding years, K. brevis blooms were present, and average growth of individually tagged mussels remained below 3 mm month(-1). During growth monitoring the use of calcein as an internal marker was tested with positive staining results and no observed effect on growth or survival. In March 2012, following the first red tide bloom, a population-wide mortality event was observed. Following this event, increased mortality rates were observed with peaks during onset of the bloom in the fall of 2012 and 2013. Juvenile recruitment was also limited during years in which blooms persisted into the spring spawning period suggesting gamete and/or larval sensitivity to K. brevis. Although it cannot be conclusively determined that the cause of reduced growth and survival is due to red tide events, the parallels observed suggest that K. brevis is a factor in the observed changes in population structure. PMID:26647288

  20. Comparative concentrations of brevetoxins PbTx-2, PbTx-3, BTX-B1 and BTX-B5 in cockle, Austrovenus stutchburyi, greenshell mussel, Perna canaliculus, and Pacific oyster, Crassostrea gigas, involved neurotoxic shellfish poisoning in New Zealand.

    PubMed

    Ishida, Hitoshi; Nozawa, Akira; Nukaya, Haruo; Tsuji, Kuniro

    2004-06-01

    Previously, we found brevetoxins PbTx-3, BTX-B5 and BTX-B1 in cockle, Austrovenus (A.) stutchburyi, PbTx-2, PbTx-3 and BTX-B1 in Pacific oyster, Crassostrea (C.) gigas and PbTx-3 and BTX-B1 in greenshell mussel, Perna (P.) canaliculus following outbreak of neurotoxic shellfish poisoning (NSP) in New Zealand by isolation and/or liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). In this study, procedures for quantitative determination of PbTx-2 and BTX-B5 were developed and those for PbTx-3 and BTX-B1 were further examined by LC-MS/MS. In mass spectrometry with an electrospray ionization interface operating in the positive or negative ion mode, the protonated ions [M+H]+ of PbTx-2 (m/z 895), [M+H]+ of PbTx-3 (m/z 897), [M-H]- of BTX-B5 (m/z 909), and [M-Na]- of BTX-B1 (m/z 1016) were generated abundantly, when 0.1% formic acid-acetonitrile was used as the mobile phase for column chromatography. The product ions of m/z 877, 725, 111 and 80 from PbTx-2, PbTx-3, BTX-B5 and BTX-B1 were identified, respectively, allowing unambiguous confirmation of these toxins by selective reaction monitoring LC-MS/MS analysis. High levels of PbTx-3 and BTX-B5 were detected in C. gigas, of PbTx-3, BTX-B1 and BTX-B5 in A. stutchburyi, and of PbTx-2, PbTx-3 and BTX-B5 in P. canaliculus by this LC-MS/MS method. PMID:15284012

  1. A randomized controlled trial investigating the effects of PCSO-524®, a patented oil extract of the New Zealand green lipped mussel (Perna canaliculus), on the behaviour, mood, cognition and neurophysiology of children and adolescents (aged 6–14 years) experiencing clinical and sub-clinical levels of hyperactivity and inattention: study protocol ACTRN12610000978066

    PubMed Central

    2013-01-01

    Background The prevalence rate of attention-deficit/hyperactivity disorder (ADHD) within Western cultures is between 5% and 12%, and is the most common psychiatric illness among school-aged children, with an estimated 50% of these children retaining ADHD symptoms for the rest of their lives. Children with ADHD have lower blood levels of long-chain Poly Unsaturated Fatty Acids (LC PUFAs) compared with children without ADHD, and following PUFA supplementation, have shown improvements in ADHD-related symptoms. One highly promising marine based LC PUFA preparation is the Omega-3-rich Lyprinol/Omega XL which is a natural formulation containing standardised lipid extract of the New Zealand green lipped mussel (Perna canaliculus) known as PCSO-524® which contains a unique combination of free fatty acids, sterol esters, polar lipids and carotenoids. It is this unique combination of marine lipids that may assist in correcting the decreased levels of LC PUFA levels in children with symptoms of ADHD. The compound is a mixture belonging to a lipid group called sterol esters (SE). The fatty acids in the SE fraction are mainly myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Lyprinol/Omega XL has previously been shown to contain a potent group of Omega-3 lipids that block the 5 - lipoxygenase metabolic pathway responsible for inflammation in the body. Methods A randomized double blind placebo controlled trial will be utilized to assess the effects of 14 weeks administration of Lyprinol/Omega XL versus placebo in 150 children aged 6 to 14 years with high levels of hyperactivity and inattention. Additionally, a range of cognitive, mood and central electrophysiological measures will be undertaken during the 14 week supplementation trial. The primary outcome measure, the Conners’ Parent Rating Scales will be completed initially at baseline, then in weeks 4, 8, 10, 14 and then

  2. Assessment of trace element contamination and bioaccumulation in algae (Ulva lactuca), mussels (Perna perna), shrimp (Penaeus kerathurus), and fish (Mugil cephalus, Saratherondon melanotheron) along the Senegalese coast.

    PubMed

    Diop, Mamadou; Howsam, Michael; Diop, Cheikh; Goossens, Jean F; Diouf, Amadou; Amara, Rachid

    2016-02-15

    Concentrations of 11 elements were quantified in five marine species from different trophic levels of a food web (algae, mussel, shrimp and fish), representative for shallow Senegalese coastal waters, and including species of commercial importance. Significant differences in element concentrations and bioaccumulation were demonstrated, revealing the utility of employing a suite of organisms as bioindicators to monitor metal contamination in coastal areas. There was no clear seasonal pattern in concentration of elements, however inter-site differences were observed. Calculations of transfer factors for all the studied elements showed that transfer factors from water were greater than those from sediments. For shrimp and mussel, the concentrations of Pb and Cd were below the EU's maximum level for human consumption, however high concentrations of arsenic in shrimp were recorded at all sites. PMID:26763317

  3. Evaluating Complementary Therapies for Canine Osteoarthritis Part I: Green-lipped Mussel (Perna canaliculus)

    PubMed Central

    Tulamo, Riitta-Mari; Salonen, Hanna; Raekallio, Marja

    2009-01-01

    A green-lipped mussel (GLM) preparation was evaluated in a randomized, double-controlled and double-blinded clinical trial. It was hypothesized that the treatment effect would be less than that of the positive control (carprofen) but more than that of the negative control (placebo). Forty-five dogs with chronic pain and a radiographic diagnosis of osteoarthritis that were randomly allocated into one of three groups completed the study. All dogs were fed the test products or placebo for 8 weeks. The dogs were evaluated four times, at 4-week intervals. Six different variables were assessed: veterinary-assessed mobility index, two force plate variables, owner-evaluated chronic pain index and pain as well as locomotion visual analogue scales (VASs). Intake of extra carprofen was also evaluated. A chi-squared and a Mann–Whitney test were used to determine significance between groups. When changed to dichotomous variables, there were more dogs in the GLM than in the placebo group that improved, according to veterinary-assessed mobility, owner-evaluated chronic pain index and pain VAS (P = 0.031, P = 0.025, P = 0.011, respectively). For the same three, the odds ratio and their confidence interval were over one. The extent of improvement was significantly different between the GLM and the control in veterinary-assessed mobility (P = 0.012) and pain VAS (P = 0.004). In conclusion, GLM alleviated chronic orthopedic pain in dogs although it was not as effective as carprofen. As no side-effects were detected, GLM may be beneficial in dogs e.g. when non-steroidal anti-inflammatory drugs cannot be used. PMID:18955269

  4. Eleven novel polymorphic microsatellite DNA markers from the green-lipped mussel Perna viridis.

    PubMed

    Ong, C C; Teh, C H; Tan, S G; Yusoff, K; Yap, C K

    2008-04-01

    We report on the characterization of 11 polymorphic microsatellite loci in P. viridis, the first set of such markers developed and characterized for this species. The number of alleles per locus ranged from 2 to 7, whereas the observed heterozygosity ranged from 0.0447 to 0.4837. These markers should prove useful as powerful genetic markers for this species. PMID:18666563

  5. Cloning, expression and identification of two glutathione S-transferase isoenzymes from Perna viridis.

    PubMed

    Li, Zhenzhen; Chen, Rong; Zuo, Zhenghong; Mo, Zhengping; Yu, Ang

    2013-08-01

    Glutathione S-transferases (GSTs; EC 2.5.1.18) are phase II enzymes involved in major detoxification reactions of xenobiotic in many organisms. In the present study, two classes of GSTs (PvGST1 and PvGST2) were cloned from P. viridis by rapid amplification of cDNA ends method. Sequence alignments and phylogenetic analysis together supported that PvGST1 and PvGST2 belonged to the pi and omega classes, respectively. The PvGST1 cDNA was 1214 nucleotides (nt) in length and contained a 618 nt open reading frame (ORF) encoding 206 amino acid residues, and had 46 nt of 5'-untranslated region (UTR) and a 3' UTR of 550 nt including a tailing signal (AATAAA) and a poly (A) tail. The molecular mass of the predicted PvGST1 was 23.815kDa, with the calculated isoelectric point being 5.39. PvGST2 was 1093bp, consisting of a 5' UTR of 13bp, a 3' UTR of 246bp and an ORF of 834bp. The deduced protein was composed of 278 amino acids, with an estimated molecular mass of 32.476kDa and isoelectric point of 8.88. Tissue distribution analysis of the PvGST1 and PvGST2 mRNA revealed that the GST expression level was higher in digestive gland and gonad, while lower in gill and mantle in both genders. Molecular modeling analysis of two GSTs implicated their various functions account for their different enzymatic features. PMID:23711756

  6. High mortality and poor growth of green mussels, Perna viridis, in high chlorophyll- a environment

    NASA Astrophysics Data System (ADS)

    Soon, Tan Kar; Denil, Delta Jenetty; Ransangan, Julian

    2016-03-01

    The current study was carried out from May 2014 to April 2015 to estimate the stock status of P. viridis in Marudu Bay. The gonad development was monitored by histological examination, while the population parameters including asymptotic length ( L ∞), growth coefficient ( K), mortality rate ( Z, F and M), exploitation level ( E) and recruitment of P. viridis were estimated using the lengthfrequency data. Results of the current study demonstrated that P. viridis in Marudu Bay spawned throughout the year with two major peaks, one in April to May and another one in October to December. The recruitment pattern was continuous with the peak in May to June 2014, which corresponded to the first spawning peak in April. However, no significant recruitment was observed from the second spawning peak due to the difference in spawning timing between male and female populations. The estimated asymptotic length ( L ∞), growth coefficient ( K), total mortality ( Z), natural mortality ( M), fishing mortality ( F) and growth performance ( φ) of P. viridis in Marudu Bay were estimate to be 117 mm, 0.97 yr-1, 4.39 yr-1, 1.23 yr-1, 3.16 yr-1 and 4.123, respectively. The exponent b of the lengthweight relationship was 2.4 and exploitation level ( E) was 0.72. The high mortality, low condition indices and negative allometric of P. viridis in Marudu Bay is caused by a lack of suitable food in the surrounding water.

  7. VizieR Online Data Catalog: Taxonomy of potentially hazardous asteroids (Perna+, 2016)

    NASA Astrophysics Data System (ADS)

    Perna, D.; Dotto, E.; Ieva, S.; Barucci, M. A.; Bernardi, F.; Fornasier, S.; de Luise, F.; Perozzi, E.; Rossi, A.; Epifani, E. M.; Micheli, M.; Deshapriya, J. D. P.

    2016-07-01

    Observations of 14 Potentially Hazardous Asteroids (PHAs) were carried out at the 3.6-m Telescopio Nazionale Galileo (TNG, La Palma, Spain), the ESO 3.6-m New Technology Telescope (NTT, La Silla, Chile), and the NASA 3.0-m Infrared Telescope Facility (IRTF, Mauna Kea, USA). The observational circumstances, as well as the instrumentation used are given in Table1. According to the population model by Mainzer et al. (2012ApJ...752..110M), ~4700+/-1450 PHAs are expected to exist. To further investigate the PHA population as a whole, and in particular to verify how the different taxonomic types are distributed with respect to other physical and dynamical properties, we combined our results with the available literature. We started retrieving the European Asteroid Research Node (EARN; http://earn.dlr.de/; retrieved on 2015 April 28) database of Near-Earth Object (NEO) physical properties, selecting those 255 Potentially Hazardous Asteroids (PHAs) with published taxonomic classifications. Of our 14 targets, 7 are classified in the present work for the first time, for a total sample of 262 targets to be considered in our analysis (see Table4). The results for our remaining seven targets are in agreement with the literature. (2 data files).

  8. Fauna Europaea: Mollusca – Bivalvia

    PubMed Central

    2015-01-01

    Abstract Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. For the Mollusca-Bivalvia, data from 5 families (Margaritiferidae, Unionidae, Sphaeriidae, Cyrenidae, Dreissenidae) containing 55 species are included in this paper. European freshwater bivalves belong to the Orders Unionoida and Cardiida. All the European unionoids are included in the superfamily Unionoidea, the freshwater mussels or naiads. The European cardiids belong to the following three superfamilies: Cardioidea, Cyrenoidea and Dreissenoidea. Among the Unionoidea there are the most imperilled animal groups on the planet while the Cardioidea includes the cosmopolitan genus Pisidium, the Cyrenoidea the Asiatic clam (Corbicula fluminea) and the Dreissenoidea the famous invasive zebra mussel (Dreissena polymorpha). Basic information is summarized on their taxonomy and biology. Tabulations include a complete list of the current estimated families, genera and species. PMID:26311403

  9. Dwarf males in the teredinidae (bivalvia, pholadacea).

    PubMed

    Turner, R D; Yakovlev, Y

    1983-03-01

    Extreme sexual dimorphism in the Bivalvia is rare. The occurrence of dwarf males in Zachsia appears to be the first case in the Teredinidae and the first outside the Leptonacea. Female Zachsia release straight-hinge larvae that develop in the plankton and settle on living rhizomes of Phyllospadix. Larvae entering mantle pouches of females become males. Evolution of this life history pattern is tied to problems of living in a fragile, patchy habitat-that is, the rhizomes of Phyllospadix. PMID:17811751

  10. Changes of Allozymes (GOT, EST and ME) of Perna viridis Subjected to Zinc Stress: A Laboratory Study

    NASA Astrophysics Data System (ADS)

    Yap, C. K.; Tan, S. G.

    It had been documented through electrophoretic studies that allozyme polymorphisms of bivalve populations are affected by heavy metal stress. In the present laboratory study, by using P. viridis as a test organism, the results indicated that changes in the enzymes GOT, EST and ME were due to Zn stress which are complemented by reductions of filtration rate and condition index. However, it is not yet known for sure whether the enzymes GOT, EST and ME are inducing behavioural and other changes in P. viridis. This is because of the possible subtle interactions could occur between different environmental stresses.

  11. Comparative effects of the blue green algae Nodularia spumigena and a lysed extract on detoxification and antioxidant enzymes in the green lipped mussel (Perna viridis).

    PubMed

    Davies, Warren R; Siu, William H L; Jack, Ralph W; Wu, Rudolf S S; Lam, Paul K S; Nugegoda, Dayanthi

    2005-01-01

    Nodularia spumigena periodically proliferates to cause toxic algal blooms with some aquatic animals enduring and consuming high densities of the blue green algae or toxic lysis. N. spumigena contains toxic compounds such as nodularin and lipopolysaccharides. This current work investigates physiological effects of exposure from bloom conditions of N. spumigena cells and a post-bloom lysis. Biochemical and antioxidative biomarkers were comparatively studied over an acute 3-day exposure. In general, a post-bloom N. spumigena lysis caused opposite physiological responses to bloom densities of N. spumigena. Specifically, increases in glutathione (GSH) and glutathione peroxidase (GPx) and decreases in glutathione S-transferase (GST) were observed from the N. spumigena lysis. In contrast, N. spumigena cell densities decreased GSH and increased GST and lipid peroxidation (LPO) in mussels. Findings also suggest that at different stages of a toxic bloom, exposure may result in toxic stress to specific organs in the mussel. PMID:16291202

  12. Preparation of gluten free bread enriched with green mussel (Perna canaliculus) protein hydrolysates and characterization of peptides responsible for mussel flavour.

    PubMed

    Vijaykrishnaraj, M; Roopa, B S; Prabhasankar, P

    2016-11-15

    Green mussel protein hydrolysates (GMPH) utilization for the enrichment of gluten-free bread followed by characterization of flavour peptides using chromatography and electronic nose techniques have been done. The degree of hydrolysis was carried out in each protease digest, and the higher degree of hydrolysis was observed in pepsin digestion. Gluten-free (GF) bread was formulated by using buckwheat flour (BWF), rice flour (RF) and chickpea flour (CPF) (70:20:10) and GMPH were added in the range of 0-20% in the GF bread for enrichment with GMPH. Radar plot of the electronic nose analysis showed that the sensors P30/2, T30/1 and T70/2 had a higher response to the GF bread and GMPH. Consequently, the peptide sequence was obtained manually by ESI-MS spectra of GMPH (KGYSSYICDK) and F-II (SSYCIVKICDK). Flavour quality was 97% discriminately comparable to the GMPH and F-II fractions. Mussel flavoured GF bread can be included in the celiac diet. PMID:27283688

  13. Comparative genomics of vesicomyid clam (Bivalvia: Mollusca) chemosynthetic symbionts

    PubMed Central

    Newton, Irene LG; Girguis, Peter R; Cavanaugh, Colleen M

    2008-01-01

    Background The Vesicomyidae (Bivalvia: Mollusca) are a family of clams that form symbioses with chemosynthetic gamma-proteobacteria. They exist in environments such as hydrothermal vents and cold seeps and have a reduced gut and feeding groove, indicating a large dependence on their endosymbionts for nutrition. Recently, two vesicomyid symbiont genomes were sequenced, illuminating the possible nutritional contributions of the symbiont to the host and making genome-wide evolutionary analyses possible. Results To examine the genomic evolution of the vesicomyid symbionts, a comparative genomics framework, including the existing genomic data combined with heterologous microarray hybridization results, was used to analyze conserved gene content in four vesicomyid symbiont genomes. These four symbionts were chosen to include a broad phylogenetic sampling of the vesicomyid symbionts and represent distinct chemosynthetic environments: cold seeps and hydrothermal vents. Conclusion The results of this comparative genomics analysis emphasize the importance of the symbionts' chemoautotrophic metabolism within their hosts. The fact that these symbionts appear to be metabolically capable autotrophs underscores the extent to which the host depends on them for nutrition and reveals the key to invertebrate colonization of these challenging environments. PMID:19055818

  14. A phylogenetic backbone for Bivalvia: an RNA-seq approach

    PubMed Central

    González, Vanessa L.; Andrade, Sónia C. S.; Bieler, Rüdiger; Collins, Timothy M.; Dunn, Casey W.; Mikkelsen, Paula M.; Taylor, John D.; Giribet, Gonzalo

    2015-01-01

    Bivalves are an ancient and ubiquitous group of aquatic invertebrates with an estimated 10 000–20 000 living species. They are economically significant as a human food source, and ecologically important given their biomass and effects on communities. Their phylogenetic relationships have been studied for decades, and their unparalleled fossil record extends from the Cambrian to the Recent. Nevertheless, a robustly supported phylogeny of the deepest nodes, needed to fully exploit the bivalves as a model for testing macroevolutionary theories, is lacking. Here, we present the first phylogenomic approach for this important group of molluscs, including novel transcriptomic data for 31 bivalves obtained through an RNA-seq approach, and analyse these data with published genomes and transcriptomes of other bivalves plus outgroups. Our results provide a well-resolved, robust phylogenetic backbone for Bivalvia with all major lineages delineated, addressing long-standing questions about the monophyly of Protobranchia and Heterodonta, and resolving the position of particular groups such as Palaeoheterodonta, Archiheterodonta and Anomalodesmata. This now fully resolved backbone demonstrates that genomic approaches using hundreds of genes are feasible for resolving phylogenetic questions in bivalves and other animals. PMID:25589608

  15. A phylogenetic backbone for Bivalvia: an RNA-seq approach.

    PubMed

    González, Vanessa L; Andrade, Sónia C S; Bieler, Rüdiger; Collins, Timothy M; Dunn, Casey W; Mikkelsen, Paula M; Taylor, John D; Giribet, Gonzalo

    2015-02-22

    Bivalves are an ancient and ubiquitous group of aquatic invertebrates with an estimated 10 000-20 000 living species. They are economically significant as a human food source, and ecologically important given their biomass and effects on communities. Their phylogenetic relationships have been studied for decades, and their unparalleled fossil record extends from the Cambrian to the Recent. Nevertheless, a robustly supported phylogeny of the deepest nodes, needed to fully exploit the bivalves as a model for testing macroevolutionary theories, is lacking. Here, we present the first phylogenomic approach for this important group of molluscs, including novel transcriptomic data for 31 bivalves obtained through an RNA-seq approach, and analyse these data with published genomes and transcriptomes of other bivalves plus outgroups. Our results provide a well-resolved, robust phylogenetic backbone for Bivalvia with all major lineages delineated, addressing long-standing questions about the monophyly of Protobranchia and Heterodonta, and resolving the position of particular groups such as Palaeoheterodonta, Archiheterodonta and Anomalodesmata. This now fully resolved backbone demonstrates that genomic approaches using hundreds of genes are feasible for resolving phylogenetic questions in bivalves and other animals. PMID:25589608

  16. [Growth and survival of the green mussel P. viridis (Bivalvia: Mytilidae) in bottom culture conditions in Turpialito, Golfo de Cariaco, Venezuela].

    PubMed

    Acosta, Vanessa; Montes, Marbelis; Cortez, Roraysi; Guevara, Miguel; Lodeiros, César

    2012-12-01

    Mussels represent one of the most important mollusk species for culture activities around the world, and their growth may depend on the culture system used and locality. In this study, we evaluated the growth of Perna viridis in bottom culture to test its performance when using natural food, and to decide its use as a culture species in the Gulf of Cariaco. For this, mussel seeds (35.81 +/- 1.41 mm in length) were obtained in the locality of Guaca (North coast of Sucre state) and transferred to the Hydrobiological Station of Turpialito, Gulf of Cariaco, Sucre state, Venezuela, where they were planted in "Spanish baskets" to evaluate their growth between July 2007 and February 2008. Monthly survival was determined and the maximum shell length, dry mass of muscle and remains tissues of the gonad. The environmental parameters (water temperature, salinity, dissolved oxygen, chlorophyll a, total seston and organic fraction), in the cultivation area were determined every 15 days. Monthly measurements were made of proteins, lipids and carbohydrates to seston. During the entire study the mussels showed continued growth, ultimately reaching a maximum length of 78.7 +/- 4.43 mm. However, the growth rate of the dry mass of somatic (muscle, other tissue) and reproductive tissues showed variability throughout the study, and observed a significant increase by the end of the experiment. The observed variations in the growth rate of the reproductive tissue mass depended on the reserves accumulated and food offered by the environment. The organic seston throughout the experience showed an independence of temperature and chlorophyll a values; this one maintained values above 1 mg/L, thus forming the main food resource for mussels. The high content of proteins, lipids and carbohydrates observed in the seston at the end of the study, might be mainly associated with coastal upwelling, which provides a great food contribution of phytoplankton and organic type. The high survival rate

  17. Bathymetric distribution patterns of Southern Ocean macrofaunal taxa: Bivalvia, Gastropoda, Isopoda and Polychaeta

    NASA Astrophysics Data System (ADS)

    Brandt, Angelika; Linse, Katrin; Schüller, Myriam

    2009-11-01

    The aim of this study is to compare the depth distributions of four major Southern Ocean macrobenthic epi- and infaunal taxa, the Bivalvia, Gastropoda, Isopoda, and Polychaeta, from subtidal to abyssal depth. All literature data up to summer 2008, as well as the unpublished data from the most recent ANDEEP I-III (Antarctic benthic deep-sea biodiversity: colonisation history and recent community patterns) expeditions to the Southern Ocean deep sea are included in the analysis. Benthic invertebrates in the Southern Ocean are known for their wide bathymetric ranges. We analysed the distributions of four of the most abundant and species-rich taxa from intertidal to abyssal (5200 m) depths in depth zones of 100 m. The depth distributions of three macrofaunal classes (Bivalvia, Gastropoda, Polychaeta) and one order (Isopoda) showed distinct differences. In the case of bivalves, gastropods and polychaetes, the number of species per depth zone decreased from the shelf to the slope at around 1000 m depth and then showed stable low numbers. The isopods showed the opposite trend; they were less species rich in the upper 1000 m but increased in species numbers from the slope to bathyal and abyssal depths. Depth ranges of families of the studied taxa (Bivalvia: 31 families, Gastropoda: 60, Isopoda: 32, and Polychaeta: 46 families) were compiled and illustrated. At present vast areas of the deep sea in the Southern Ocean remain unexplored and species accumulation curves showed that only a fraction of the species have been discovered to date. We anticipate that further investigations will greatly increase the number of species known in the Southern Ocean deep sea.

  18. First report of Perkinsus beihaiensis in wild clams Anomalocardia brasiliana (Bivalvia: Veneridae) in Brazil.

    PubMed

    Pinho Ferreira, Liana; Sabry, Rachel Costa; da Silva, Patrícia Mirella; Gesteira, Tereza Cristina Vasconcelos; de Souza Romão, Lidiane; Paz, Marcela Pinheiro; Feijó, Rubens Galdino; Neto, Maximiano Pinheiro Dantas; Maggioni, Rodrigo

    2015-03-01

    This is the first report of Perkinsus sp. (Bivalvia: Veneridae) infecting wild clams of the species Anomalocardia brasiliana in Brazil. The gill lamellae and rectum of 150 specimens of A. brasiliana collected in the Timonha river estuary (Ceará, Northeastern Brazil) in March 2012 were incubated in Ray's fluid thioglycollate medium (RFTM) for detection of Perkinsus sp. In RFTM, the prevalence of Perkinsus sp. was 14.7% (22/150) and the intensity of infection ranged from very light (1-10 cells across the slide) to light (12-100 cells). The presence of Perkinsus sp. was confirmed by PCR in seven (31.8%) out of 22 RFTM-positive specimens. DNA sequencing confirmed the presence of the genus Perkinsus and the phylogenetic analysis strongly indicated Perkinsus beihaiensis as the species responsible for the infection. PMID:25088443

  19. [Are the contours of the frontal section of shell valves in Bivalvia specific?].

    PubMed

    Voroshilova, I S

    2013-01-01

    The diagnostic importance of the character of curvature of the frontal section of shell valves in Bivalvia on the basis of determining the constant angle of the logarithmic spiral is discussed. The contours of the frontal section of shell valves in several species of mollusks of the families Margaritiferidae and Sphaeriidae have been analyzed. It is shown that in different species of the family Sphaeriidae, the values of constant angles coincide. While performing graphic constructions, it was established that the contours of the frontal section of all studied species of pearl mussels and some spheriids do not correspond to the segment of the logarithmic spiral. It was noted that the hypothesis of the species specificity of this character was not confirmed; therefore, the curvature of the frontal section of shell valves cannot be used as the main character for the systematics and species identification of bivalves. PMID:24171313

  20. Spermatozoa and spermatogenesis in the northern quahaug Mercenaria mercenaria (Mollusca, Bivalvia)

    NASA Astrophysics Data System (ADS)

    Ying, Xue-Ping; Yang, Wan-Xi; Dahms, Hans-U.; Lin, Zhihua; Chai, Xueliang

    2008-12-01

    We studied the ultrastructure of spermatogenesis and spermatozoa in the northern quahaug, the clam Mercenaria mercenaria. Spermatogenetic cells gradually elongate. Mitochondria gradually fuse and increase in size and electron density. During spermatid differentiation, proacrosomal vesicles migrate towards the presumptive anterior pole of the nucleus and eventually form the acrosome. The spermatozoon of M. mercenaria is of a primitive type. It is composed of head, mid-piece, and tail. The acrosome shows a subacrosomal space with a short conical contour. The slightly curved nucleus of the spermatozoon contains fine-grained dense chromatin. The middle piece consists of a centriolar complex which is surrounded by four mitochondria. The flagellum has a standard “9 + 2” microtubular structure. The ultrastructure of spermatozoa and spermatogenesis of M. mercenaria shares a number of features with other species of the family Veneridae. M. mercenaria may be a suitable model species for further investigations into the mechanisms of spermatogenesis in the Bivalvia.

  1. The Rho GTPase Family Genes in Bivalvia Genomes: Sequence, Evolution and Expression Analysis

    PubMed Central

    Li, Xue; Wang, Ruijia; Xun, Xiaogang; Jiao, Wenqian; Zhang, Mengran; Wang, Shuyue; Wang, Shi; Zhang, Lingling; Huang, Xiaoting; Hu, Xiaoli; Bao, Zhenmin

    2015-01-01

    Background Rho GTPases are important members of the Ras superfamily, which represents the largest signaling protein family in eukaryotes, and function as key molecular switches in converting and amplifying external signals into cellular responses. Although numerous analyses of Rho family genes have been reported, including their functions and evolution, a systematic analysis of this family has not been performed in Mollusca or in Bivalvia, one of the most important classes of Mollusca. Results In this study, we systematically identified and characterized a total set (Rho, Rac, Mig, Cdc42, Tc10, Rnd, RhoU, RhoBTB and Miro) of thirty Rho GTPase genes in three bivalve species, including nine in the Yesso scallop Patinopecten yessoensis, nine in the Zhikong scallop Chlamys farreri, and twelve in the Pacific oyster Crassostrea gigas. Phylogenetic analysis and interspecies comparison indicated that bivalves might possess the most complete types of Rho genes in invertebrates. A multiple RNA-seq dataset was used to investigate the expression profiles of bivalve Rho genes, revealing that the examined scallops share more similar Rho expression patterns than the oyster, whereas more Rho mRNAs are expressed in C. farreri and C. gigas than in P. yessoensis. Additionally, Rho, Rac and Cdc42 were found to be duplicated in the oyster but not in the scallops. Among the expanded Rho genes of C. gigas, duplication pairs with high synonymous substitution rates (Ks) displayed greater differences in expression. Conclusion A comprehensive analysis of bivalve Rho GTPase family genes was performed in scallop and oyster species, and Rho genes in bivalves exhibit greater conservation than those in any other invertebrate. This is the first study focusing on a genome-wide characterization of Rho GTPase genes in bivalves, and the findings will provide a valuable resource for a better understanding of Rho evolution and Rho GTPase function in Bivalvia. PMID:26633655

  2. The histopathology of the infection of Tilapia rendalli and Hypostomus regani (Osteichthyes) by lasidium larvae of Anodontites trapesialis (Mollusca, Bivalvia).

    PubMed

    Silva-Souza, Angela Teresa; Eiras, Jorge C

    2002-04-01

    It is described the histopathology of the infection of Tilapia rendalli (Osteichthyes, Perciformes, Cichlidae) and Hypostomus regani (Osteichthyes, Siluriformes, Loricariidae) by lasidium larvae of Anodontites trapesialis (Mollusca, Bivalvia, Mycetopodidae). The larvae were encysted within the epidermis of the host, being surrounded by a thin hyaline membrane, 3-6 microm thick, of parasite origin. A proliferative host cell reaction did not occur. The histopathology of the infection shows that the lesions induced by the parasites are minimal. However, the numerous small lesions produced by the release of the larvae may provide optimal conditions for the infection by opportunistic pathogens, namely fungus, which may eventually cause the death of the host. PMID:12048579

  3. Nanoindentations on conch shells of Gastropoda and Bivalvia molluscs reveal anisotropic evolution against external attacks.

    PubMed

    Bignardi, Cristina; Petraroli, Michele; Pugno, Nicola M

    2010-10-01

    Nanoindentation method has been used to explore, at the nanoscale, the mechanical properties of four different representative types of conch shells belonging to the two biggest classes of molluscs, Gastropoda and Bivalvia, in order to compare nanohardness and Young's modulus with respect to the microstructural anisotropic architectures. For the experimental tests a Nano Indenter XP (MTS Nano Instruments, Oak Ridge TN) has been used. The mechanical tests have been carried out on the inner and outer surfaces of the shells, as well as on their cross-section, near to the inner/outer surfaces and in the middle layer. The results confirm the three layered anisotropic architecture of the investigated conchs. On each of these 5 surfaces, 2 x 5 indentations have been performed at different maximum depth: from 250 nm to 4 microm, with a step of 250 nm, for a total of 3200 tests. The numerous observations have been analysed applying an ad hoc modification of the Weibull Statistics, suggesting a natural evolution of the shells against external attacks. PMID:21137746

  4. Systematics and distribution of Cristaria plicata (Bivalvia, Unionidae) from the Russian Far East

    PubMed Central

    Klishko, Olga K.; Lopes-Lima, Manuel; Froufe, Elsa; Bogan, Arthur E.; Abakumova, Vera Y.

    2016-01-01

    Abstract The number of anodontine bivalve species placed in the genus Cristaria (Bivalvia, Unionidae) from the Russian Far East is still not stable among authors. Some recognize only one valid species Cristaria plicata (Leach, 1815) while others accept two additional species, Cristaria tuberculata Schumacher, 1817 and Cristaria herculea (Middendorff, 1847). In the present study, these taxonomic doubts are addressed using analyses of mitochondrial DNA sequences and shell morphometry. No significant differences have been revealed by the COI DNA sequences or the main statistical morphometric indices from the three Cristaria forms. In the specimens analysed, changes in shell morphometry with age suggest that original descriptions of the different forms may be attributed solely to differences in age and sex. We consider that Cristaria plicata, Cristaria tuberculata and Cristaria herculea from the Russian Far East should be considered as a single species, namely Cristaria plicata (Leach, 1815), with Cristaria tuberculata and Cristaria herculea as junior synonyms. The geographic range of Cristaria plicata and its conservation status are also presented here. PMID:27110206

  5. Systematics and distribution of Cristaria plicata (Bivalvia, Unionidae) from the Russian Far East.

    PubMed

    Klishko, Olga K; Lopes-Lima, Manuel; Froufe, Elsa; Bogan, Arthur E; Abakumova, Vera Y

    2016-01-01

    The number of anodontine bivalve species placed in the genus Cristaria (Bivalvia, Unionidae) from the Russian Far East is still not stable among authors. Some recognize only one valid species Cristaria plicata (Leach, 1815) while others accept two additional species, Cristaria tuberculata Schumacher, 1817 and Cristaria herculea (Middendorff, 1847). In the present study, these taxonomic doubts are addressed using analyses of mitochondrial DNA sequences and shell morphometry. No significant differences have been revealed by the COI DNA sequences or the main statistical morphometric indices from the three Cristaria forms. In the specimens analysed, changes in shell morphometry with age suggest that original descriptions of the different forms may be attributed solely to differences in age and sex. We consider that Cristaria plicata, Cristaria tuberculata and Cristaria herculea from the Russian Far East should be considered as a single species, namely Cristaria plicata (Leach, 1815), with Cristaria tuberculata and Cristaria herculea as junior synonyms. The geographic range of Cristaria plicata and its conservation status are also presented here. PMID:27110206

  6. Vesicomyinae (Bivalvia: Vesicomyidae) of the Kuril-Kamchatka Trench and adjacent abyssal regions

    NASA Astrophysics Data System (ADS)

    Krylova, Elena M.; Kamenev, Gennady M.; Vladychenskaya, Irina P.; Petrov, Nikolai B.

    2015-01-01

    Representatives of the subfamily Vesicomyinae (Bivalvia, Vesicomyidae) are tiny deep-sea molluscs distributed worldwide and reaching huge abundances of hundreds and thousands of specimens in trawl catches. During the German-Russian deep-sea expedition KuramBio (R/V Sonne, 2012) for the first time two vesicomyin species were collected from the abyssal plain adjacent to the Kuril-Kamchatka Trench from the depths of 4861-5787 m, Vesicomya pacifica (Smith, 1885) and "Vesicomya" filatovae sp.n. Two species of vesicomyins, V. sergeeviFilatova, 1971 and V. profundiFilatova, 1971, which were previously reported from the hadal of the Kuril-Kamchatka Trench, were not collected at the abyssal depth despite of the close geographical proximity of the sampling area to their distribution ranges. Altogether nine species of vesicomyins are recorded now from the West and Indo-West Pacific; data on distribution and morpho-anatomical characters of these species are provided. Taxonomic description of V. pacifica is revised including information on its soft part anatomy, new localities and COI sequences. For the first time for a vesicomyin bivalve molecular data is given for a species with an explicit morphological description and unambiguous taxonomic affiliation. Molecular analysis of 160 published COI sequences of vesicomyids and newly obtained molecular data on V. pacifica showed that V. pacifica and two undescribed vesicomyin species forming a monophyletic clade which exhibits sister relationships with the Pliocardiinae, the group of chemosymbiotic vesicomyids. "Vesicomya" filatovae sp.n. is provisionally assigned to the genus Vesicomya (s.l.) until additional morphological and molecular data are obtained. It differs from Vesicomya s.s. by a broader hinge margin with more radiating teeth and the presence of only one pair of demibranchs.

  7. Factors driving changes in freshwater mussel (Bivalvia, Unionida) diversity and distribution in Peninsular Malaysia.

    PubMed

    Zieritz, Alexandra; Lopes-Lima, Manuel; Bogan, Arthur E; Sousa, Ronaldo; Walton, Samuel; Rahim, Khairul Adha A; Wilson, John-James; Ng, Pei-Yin; Froufe, Elsa; McGowan, Suzanne

    2016-11-15

    Freshwater mussels (Bivalvia, Unionida) fulfil important ecosystem functions and are one of the most threatened freshwater taxa globally. Knowledge of freshwater mussel diversity, distribution and ecology in Peninsular Malaysia is extremely poor, and the conservation status of half of the species presumed to occur in the region has yet to be assessed. We conducted the first comprehensive assessment of Peninsular Malaysia's freshwater mussels based on species presence/absence and environmental data collected from 155 sites spanning all major river catchments and diverse habitat types. Through an integrative morphological-molecular approach we recognised nine native and one widespread non-native species, i.e. Sinanodonta woodiana. Two species, i.e. Pilsbryoconcha compressa and Pseudodon cambodjensis, had not been previously recorded from Malaysia, which is likely a result of morphological misidentifications of historical records. Due to their restriction to single river catchments and declining distributions, Hyriopsis bialata, possibly endemic to Peninsular Malaysia, Ensidens ingallsianus, possibly already extinct in the peninsula, and Rectidens sumatrensis, particularly require conservation attention. Equally, the Pahang, the Perak and the north-western river catchments are of particular conservation value due to the presence of a globally unique freshwater mussel fauna. Statistical relationships of 15 water quality parameters and mussel presence/absence identified acidification and nutrient pollution (eutrophication) as the most important anthropogenic factors threatening freshwater mussel diversity in Peninsular Malaysia. These factors can be linked to atmospheric pollution, deforestation, oil-palm plantations and a lack of functioning waste water treatment, and could be mitigated by establishing riparian buffers and improving waste water treatment for rivers running through agricultural and residential land. PMID:27473771

  8. Molecular phylogeny of pearl oysters and their relatives (Mollusca, Bivalvia, Pterioidea)

    PubMed Central

    2010-01-01

    Background The superfamily Pterioidea is a morphologically and ecologically diverse lineage of epifaunal marine bivalves distributed throughout the tropical and subtropical continental shelf regions. This group includes commercially important pearl culture species and model organisms used for medical studies of biomineralization. Recent morphological treatment of selected pterioideans and molecular phylogenetic analyses of higher-level relationships in Bivalvia have challenged the traditional view that pterioidean families are monophyletic. This issue is examined here in light of molecular data sets composed of DNA sequences for nuclear and mitochondrial loci, and a published character data set of anatomical and shell morphological characters. Results The present study is the first comprehensive species-level analysis of the Pterioidea to produce a well-resolved, robust phylogenetic hypothesis for nearly all extant taxa. The data were analyzed for potential biases due to taxon and character sampling, and idiosyncracies of different molecular evolutionary processes. The congruence and contribution of different partitions were quantified, and the sensitivity of clade stability to alignment parameters was explored. Conclusions Four primary conclusions were reached: (1) the results strongly supported the monophyly of the Pterioidea; (2) none of the previously defined families (except for the monotypic Pulvinitidae) were monophyletic; (3) the arrangement of the genera was novel and unanticipated, however strongly supported and robust to changes in alignment parameters; and (4) optimizing key morphological characters onto topologies derived from the analysis of molecular data revealed many instances of homoplasy and uncovered synapomorphies for major nodes. Additionally, a complete species-level sampling of the genus Pinctada provided further insights into the on-going controversy regarding the taxonomic identity of major pearl culture species. PMID:21059254

  9. Unionid bivalves (Mollusca: Bivalvia: Unionidae) of Presque Isle Bay, Erie, Pennsylvania

    USGS Publications Warehouse

    Masteller, E.C.; Maleski, K.R.; Schloesser, D.W.

    1993-01-01

    The purpose of this study was to determine species composition and relative abundance of unionid bivalves (Mollusca: Bivalvia: Unionidae) in Presque Isle Bay, Erie, Pennsylvania 1990-1992. This information was compared with data from the only other extensive survey of unionids in the bay conducted in 1909-1911 (Ortmann 1919) to assess changes over the 80 years preceding the present study. A total of 1,540 individuals representing 18 species were collected in 1990-1992. Five relatively common species (between 7 and 42% of total individuals), six uncommon species (2 and 6%), and seven rare species (<1%) were found. The rare species were Anodontoides ferussacianus, Lasmigona costata, Ligumia recta, Ptychobranchus fasciolaris, Quadrula pustulosa pustulosa, Strophitus undaulatus, and Truncilla donaciformis. Five of the species found in Presque Isle Bay (Leptodea fragilis, Ligumia nasuta, Potamilus alatus, Quadrula quadrula, and Truncilla donaciformis) are listed as critically imperiled and one species (Truncilla truncata) as extirpated in the State of Pennsylvania by the Western Pennsylvania Conservancy. Comparisons between unionid populations in 1909-1911 and 1990-1992 indicate few substantial changes occurred during the past 80 years. A total of 22 species were found; 21 in 1909-1911 and 18 in 1990-1992. Seventeen species were found in both studies, an additional four in 1909-1911 and one in 1990-1992. The relative abundance of 11 of the 17 species found in both studies remained stable (i.e., common or uncommon) over the past 80 years. Only four species listed as uncommon in 1909-1911 were listed as rare in 1990-1992. However, the invasion of the zebra mussel (Dreissena polymorpha) is considered a threat to the continued existence of the entire Unionidae fauna in Presque Isle Bay, a unique habitat of the Great Lakes.

  10. Molecular phylogeny of Pholadoidea Lamarck, 1809 supports a single origin for xylotrophy (wood feeding) and xylotrophic bacterial endosymbiosis in Bivalvia.

    PubMed

    Distel, Daniel L; Amin, Mehwish; Burgoyne, Adam; Linton, Eric; Mamangkey, Gustaf; Morrill, Wendy; Nove, John; Wood, Nicole; Yang, Joyce

    2011-11-01

    The ability to consume wood as food (xylotrophy) is unusual among animals. In terrestrial environments, termites and other xylotrophic insects are the principle wood consumers while in marine environments wood-boring bivalves fulfill this role. However, the evolutionary origin of wood feeding in bivalves has remained largely unexplored. Here we provide data indicating that xylotrophy has arisen just once in Bivalvia in a single wood-feeding bivalve lineage that subsequently diversified into distinct shallow- and deep-water branches, both of which have been broadly successful in colonizing the world's oceans. These data also suggest that the appearance of this remarkable life habit was approximately coincident with the acquisition of bacterial endosymbionts. Here we generate a robust phylogeny for xylotrophic bivalves and related species based on sequences of small and large subunit nuclear rRNA genes. We then trace the distribution among the modern taxa of morphological characters and character states associated with xylotrophy and xylotrepesis (wood-boring) and use a parsimony-based method to infer their ancestral states. Based on these ancestral state reconstructions we propose a set of plausible hypotheses describing the evolution of symbiotic xylotrophy in Bivalvia. Within this context, we reinterpret one of the most remarkable progressions in bivalve evolution, the transformation of the "typical" myoid body plan to create a unique lineage of worm-like, tube-forming, wood-feeding clams. The well-supported phylogeny presented here is inconsistent with most taxonomic treatments for xylotrophic bivalves, indicating that the bivalve family Pholadidae and the subfamilies Teredininae and Bankiinae of the family Teredinidae are non-monophyletic, and that the principle traits used for their taxonomic diagnosis are phylogenetically misleading. PMID:21684342

  11. Sensitivity of juvenile Macomona liliana (bivalvia) to UV-photoactivated fluoranthene toxicity.

    PubMed

    Ahrens, Michael J; Nieuwenhuis, Ronald; Hickey, Christopher W

    2002-12-01

    This study assessed the sensitivity of Macomona liliana (bivalvia, tellinacea) to UV-photoactivated fluoranthene toxicity. Juvenile clams (0.5-2.0 mm) were exposed to a range of aqueous fluoranthene concentrations (5-500 microg/L) for 96 h, after which the clams' ability to rebury in control sediment was determined. Survivors of these fluoranthene-only toxicity tests were then exposed in clean seawater to UV radiation from a solar radiation-simulating light source for 1 h. The differences between EC(50) values before and after UV exposure provided a measure of phototoxicity of the bioaccumulated fluoranthene. Fluoranthene tissue burdens corresponding to the EC(50) values were determined by exposing a second batch of clams to (14)C-radiolabeled fluoranthene. A third experiment quantified the kinetics of fluoranthene uptake and elimination in water-only exposures. Fluoranthene phototoxicity was found to depend on the dose of fluoranthene and the duration of UV exposure. Exposure of animals to 1 h of UV radiation resulted fluoranthene toxicity that was 3 times higher (EC(50) = 46 microg/L) than that of those with no UV exposure (EC(50) = 153 microg/L). The corresponding critical body burden (i.e., fluoranthene tissue concentration at which 50% of the clams failed to rebury) was 6 ng/clam (or 700 microg/g dry weight [dw]) and 21 ng/clam (or 2300 microg/g dw) for UV-exposed and UV-unexposed animals, respectively. First-order uptake and elimination coefficients, determined in the kinetics experiment, were 0.825 Lg(-1) h(-1) and 0.059 h(-1), respectively, indicating rapid uptake and a short fluoranthene tissue half-life of approximately 12 h for M. liliana. Compared with other bivalve species of similar size, M. liliana appeared to be more than 1 order of magnitude less sensitive to UV-activated fluoranthene toxicity, although these differences may be a result in part of differences in the UV exposure regime. Nonetheless, the majority of M. liliana exposed to a

  12. An unusual case of gender-associated mitochondrial DNA heteroplasmy: the mytilid Musculista senhousia (Mollusca Bivalvia)

    PubMed Central

    Passamonti, Marco

    2007-01-01

    Background Doubly Uniparental Inheritance (DUI) represents the most outstanding exception to matrilinear inheritance of mitochondrial DNA (mtDNA), typical of Metazoa. In a few bivalve mollusks, two sex-linked mtDNAs (the so-called M and F) are inherited in a peculiar way: both daughters and sons receive their F from the mother, whereas sons inherit M from the father (males do not transmit F to their progeny). This realizes a double mechanism of transmission, in which M and F mtDNAs are inherited uniparentally. DUI systems represent a unique experimental model for testing the evolutionary mechanisms that apply to mitochondrial genomes and their transmission patterns as well as to mtDNA recombination. Results A new case of DUI is described in Musculista senhousia (Mollusca: Bivalvia: Mytilidae). Its heteroplasmy pattern is in line with standard DUI. Sequence variability analysis evidenced two main results: F haplotypes sequence variability is higher than that of M haplotypes, and F mitochondrial haplotypes experience a higher mutation rate in males' somatic tissues than in females' ones. Phylogenetic analysis revealed also that M. senhousia M and F haplotypes cluster separately from that of the other mytilids. Conclusion Sequence variability analysis evidenced some unexpected traits. The inverted variability pattern (the F being more variable than M) was new and it challenges most of the rationales proposed to account for sex-linked mtDNA evolution. We tentatively related this to the history of the Northern Adriatic populations analyzed. Moreover, F sequences evidenced a higher mutation level in male's soma, this variability being produced de novo each generation. This suggests that mechanisms evolved to protect mtDNA in females (f.i. antioxidant gene complexes) might be under relaxed selection in males. Phylogenetic analysis of sex-linked haplotypes confirmed that they have switched their roles during the evolutionary history of mytilids, at variance to what has

  13. Occurrence and settlement of the common shipworm Teredo navalis (Bivalvia: Teredinidae) in Bremerhaven harbours, northern Germany

    NASA Astrophysics Data System (ADS)

    Tuente, Uda; Piepenburg, Dieter; Spindler, Michael

    2002-06-01

    The shipworm Teredo navalis L. is a xylophagous bivalve mollusc (Bivalvia: Teredinidae) with a long record of being very destructive to wooden ships and harbour buildings. It has been reported from numerous sites at the coasts of both the North and Baltic Seas since the eighteenth century. Here, we document for the first time the occurrence of live adult T. navalis in the harbours of Bremerhaven (Weser estuary, northern Germany). From August to December 1998, various wooden structures (fir floating fenders and pier posts, oak piles) from seven stations in different docks of two harbours (Überseehafen, Fischereihafen) were investigated for the presence and density of live specimens and burrows of T. navalis. The settlement of larval shipworms was studied by exposing experimental fir panels 0.06 m2 in size at 20 stations at water depths between 1 and 2 m for periods of 4 months between July and November. In addition, hydrographic profiles (0-8 m water depth) were obtained at 17 stations in five docks once every month from August to December. Live adult shipworms were found in both fir floating fenders and oak piles at four stations. The largest specimen found was 250 mm long. Shipworm burrows were detected at five stations in almost every wooden structure investigated but their abundances differed significantly: Maximum values were >10,000 m-2 in fir floating fenders, 4,600 m-2 in oak piles and 200 m-2 in fir pier posts. Actual shipworm infestation was detected at three of 16 stations in the exposed fir panels (1-3 burrow holes per panel). Water temperatures and salinities varied considerably during the 4-month investigation period. Temperatures decreased from 19.9°C in August to 0.7°C in December. Salinities ranged from 17.6 in August to 1.1 in November, but only at two lock stations during November and December did value drop below 5, which is regarded as the lethal limit for the larvae of this euryhaline teredinid species. We conclude that T. navalis encounters

  14. Gastropoda-Bivalvia Fauna And Neogene-Quaternary Stratigraphy of the Southwest of Dardanelles (Çanakkale-NWAnatolia)

    NASA Astrophysics Data System (ADS)

    Kapan, Sevinç; Kabasakal, Sinem

    2016-04-01

    Gastropoda-Bivalvia Fauna And Neogene-Quaternary Stratigraphy of the Southwest of Dardanelles (Çanakkale-NWAnatolia) Sevinç KAPAN, Sinem KABASAKAL, Çanakkale Onsekiz Mart University, Engineering Faculty, Geological Engineering Department sevinckapan_yesilyurt@hotmail.com In this study, paleontology and stratigraphy of Neogene and Quaternary units around south of the Dardanelles have been examined using Gastropoda and Bivalvia fauna. In the investigation area, the base of the sediments that belongs to Neogene, consist of the volcanics which are formed with basalts, andesites and tuff. Neogene begins unconformity with basal conglomerate which are formed with basalt and tuff gravels. The measurable thickness of the Neogene sediments is approximately 200meters in total. First fossiliferius level which consist of Lymnocardium (Euxinicardium) nobile Sabba has showed similarities with the Pontian (Late Miocene) fauna of the Eastern Paratethys. The existence of Melanopsis and Psidium species indicate that the basin has been brackish water feeding by fresh water in the Early Pliocene. Theodoxus fluviatilis (Linne), Theodoxus (Calvertia) aff. imbricata Brusina, Theodoxus (Calvertia) licherdopoli scriptus (Stefanescu), Viviparus mammatus (Stefanescu), Valvata (Valavata) sulekiana Brusina, Valvata (Cincinna) crusitensis Fontannes, Hydrobia cf grandis Cobalcescu, Hydrobia ventrosa Monfort, Melanopsis (Melanopsis) cf. bergeroni Stefanescu, , Melanopsis (Melanopsis) sandbergeri rumana Tournouer, Melanopsis (Canthidomus) hybostoma anili Taner, Melanopsis (Canthidomus) hybostoma amaradica Fontannes, Melanopsis (Canthidomus) lanceolata Neumayr, Amphimelania fossariformis (Tournouer), Melanoides tuberculata monolithica (Bukowski), Radix (Radix) peregra (Müller), Planorbarius thiollierei (Michaud), Potamida (Potamida) craiovensis craiovensis (Tournouer), Potamida (Potamida) berbestiensis (Fontannes), Unio pristinus davilai Porumbaru, Unio subexquisitus Jatzko, Anadonta zmaji

  15. Presence and histopathological effects of the Parvatrema sp. (Digenea, Gymnophallidae) in the stout razor clam Tagelus plebeius (Bivalvia, Psammobiidae).

    PubMed

    da Silva, Patricia Mirella; Cremonte, Florencia; Sabry, Rachel Costa; Rosa, Rafael Diego; Cantelli, Liege; Barracco, Margherita Anna

    2009-09-01

    The stout razor clam Tagelus plebeius (Bivalvia, Psammobiidae) has a wide geographic distribution range, including the Brazilian coasts from the northeast (Alagoas) to the south (Santa Catarina). In March 2008, an episode of mass T. plebeius mortality (70%) occurred in an intertidal bed at The Pontal da Daniela, State of Santa Catarina, Brazil. We report here high prevalences (to 100%) of the trematode parasite Parvatrema sp. Cable, 1953 (Digenea, Gymnophallidae) infecting T. plebeius at high intensities. We describe the gymnophalid, echinostomatid and unidentified metacercariae parasites infecting the clam and the host reactions elicited by them. The use of special diagnostic techniques such as Ray's fluid thioglycollate medium (RFTM) and PCR assays to detect Perkinsus sp. pathogens, hemolymph cytology, and histopathological examinations did not show Perkinsus sp. infections, microcell infections, or neoplastic conditions. However, neither infections or pathology caused by trematode parasites; nor any other pathological condition could be uniquely correlated with the mortality event. A coincident flash flood might have contributed to cause the mortality episode. This is the first report of the Parvatrema sp. metacercariae larvae infecting the stout razor clam T. plebeius from Brazil. PMID:19500587

  16. Thermal dependency of shell growth, microstructure, and stable isotopes in laboratory-reared Scapharca broughtonii (Mollusca: Bivalvia)

    NASA Astrophysics Data System (ADS)

    Nishida, Kozue; Suzuki, Atsushi; Isono, Ryosuke; Hayashi, Masahiro; Watanabe, Yusuke; Yamamoto, Yuzo; Irie, Takahiro; Nojiri, Yukihiro; Mori, Chiharu; Sato, Mizuho; Sato, Kei; Sasaki, Takenori

    2015-07-01

    We experimentally examined the growth, microstructure, and chemistry of shells of the bloody clam, Scapharca broughtonii (Mollusca: Bivalvia), reared at five temperatures (13, 17, 21, 25, and 29°C) with a constant pCO2 condition (˜450 μatm). In this species, the exterior side of the shell is characterized by a composite prismatic structure; on the interior side, it has a crossed lamellar structure on the interior surface. We previously found a negative correlation between temperature and the relative thickness of the composite prismatic structure in field-collected specimens. In the reared specimens, the relationship curve between temperature and the growth increment of the composite prismatic structure was humped shaped, with a maximum at 17°C, which was compatible with the results obtained in the field-collected specimens. In contrast, the thickness of the crossed lamellar structure was constant over the temperature range tested. These results suggest that the composite prismatic structure principally accounts for the thermal dependency of shell growth, and this inference was supported by the finding that shell growth rates were significantly correlated with the thickness of the composite prismatic structure. We also found a negative relationship between the rearing temperature and δ18O of the shell margin, in close quantitative agreement with previous reports. The findings presented here will contribute to the improved age determination of fossil and recent clams based on seasonal microstructural records.

  17. De Novo Assembly and Characterization of Two Transcriptomes Reveal Multiple Light-Mediated Functions in the Scallop Eye (Bivalvia: Pectinidae)

    PubMed Central

    Pairett, Autum N.; Serb, Jeanne M.

    2013-01-01

    Background The eye has evolved across 13 separate lineages of molluscs. Yet, there have been very few studies examining the molecular machinary underlying eye function of this group, which is due, in part, to a lack of genomic resources. The scallop (Bivalvia: Pectinidae) represents a compeling molluscan model to study photoreception due to its morphologically novel and separately evolved mirror-type eye. We sequenced the adult eye transcriptome of two scallop species to: 1) identify the phototransduction pathway components; 2) identify any additional light detection functions; and 3) test the hypothesis that molluscs possess genes not found in other animal lineages. Results A total of 3,039 contigs from the bay scallop, Argopecten irradians and 26,395 contigs from the sea scallop, Placopecten magellanicus were produced by 454 sequencing. Targeted BLAST searches and functional annotation using Gene Ontology (GO) terms and KEGG pathways identified transcripts from three light detection systems: two phototransduction pathways and the circadian clock, a previously unrecognized function of the scallop eye. By comparing the scallop transcriptomes to molluscan and non-molluscan genomes, we discovered that a large proportion of the transcripts (7,776 sequences) may be specific to the scallop lineage. Nearly one-third of these contain transmembrane protein domains, suggesting these unannotated transcripts may be sensory receptors. Conclusions Our data provide the most comprehensive transcriptomic resource currently available from a single molluscan eye type. Candidate genes potentially involved in sensory reception were identified, and are worthy of further investigation. This resource, combined with recent phylogenetic and genomic data, provides a strong foundation for future investigations of the function and evolution of molluscan photosensory systems in this morphologically and taxonomically diverse phylum. PMID:23922823

  18. Mitochondrial genomes and Doubly Uniparental Inheritance: new insights from Musculista senhousia sex-linked mitochondrial DNAs (Bivalvia Mytilidae)

    PubMed Central

    2011-01-01

    Background Doubly Uniparental Inheritance (DUI) is a fascinating exception to matrilinear inheritance of mitochondrial DNA (mtDNA). Species with DUI are characterized by two distinct mtDNAs that are inherited either through females (F-mtDNA) or through males (M-mtDNA). DUI sex-linked mitochondrial genomes share several unusual features, such as additional protein coding genes and unusual gene duplications/structures, which have been related to the functionality of DUI. Recently, new evidence for DUI was found in the mytilid bivalve Musculista senhousia. This paper describes the complete sex-linked mitochondrial genomes of this species. Results Our analysis highlights that both M and F mtDNAs share roughly the same gene content and order, but with some remarkable differences. The Musculista sex-linked mtDNAs have differently organized putative control regions (CR), which include repeats and palindromic motifs, thought to provide sites for DNA-binding proteins involved in the transcriptional machinery. Moreover, in male mtDNA, two cox2 genes were found, one (M-cox2b) 123bp longer. Conclusions The complete mtDNA genome characterization of DUI bivalves is the first step to unravel the complex genetic signals allowing Doubly Uniparental Inheritance, and the evolutionary implications of such an unusual transmission route in mitochondrial genome evolution in Bivalvia. The observed redundancy of the palindromic motifs in Musculista M-mtDNA may have a role on the process by which sperm mtDNA becomes dominant or exclusive of the male germline of DUI species. Moreover, the duplicated M-COX2b gene may have a different, still unknown, function related to DUI, in accordance to what has been already proposed for other DUI species in which a similar cox2 extension has been hypothesized to be a tag for male mitochondria. PMID:21896183

  19. A new species of freshwater mussel (Bivalvia: Unionidae), Pleurobema athearni, from the Coosa River Drainage of Alabama, USA

    USGS Publications Warehouse

    Gangloff, M.M.; Williams, J.D.; Feminella, J.W.

    2006-01-01

    The Mobile Basin historically supported one of the most diverse freshwater mussel (Bivalvia: Unionidae) assemblages in North America. More than 65 species of mussels are known from the Basin, but it is difficult to determine how many species were present historically. The drainage's unique physical habitat was largely destroyed between the late 1800s and mid-1900s by impoundment and channel modifications of most of the larger rivers. Many species that were once common are now restricted to small headwater rivers and mid-sized tributaries. Recent Coosa River tributary surveys revealed a new, undescribed species of Pleurobema. This new species, Pleurobema athearni, is distinctive in outward appearance, shell morphometry and reproductive morphology, and can be distinguished from other Coosa River drainage unionids. Our analysis indicates that P. athearni is morphologically different from other similar taxa. It differs both in shell width/length and width/height ratios and thus provides a simple, quantitative means to differentiate this species from P. georgianum (Lea, 1841) Fusconaia barnesiana (Lea, 1838), and F. cerina (Conrad, 1838), which it superficially resembles and that also occur in the area. Our morphological diagnosis of this species is supported by recent molecular analyses that suggest this species is a Pleurobema and one closely related to other endemic Coosa River drainage unionids. The discovery of a new species of large, long-lived macroinvertebrate from a relatively well-sampled drainage in a populated region of the southeast United States underscores the need for more detailed surveys in isolated stretches of tributary streams. It should also serve as a reminder that almost 40 species of aquatic mollusks have been extirpated from the Mobile Basin before anything could be learned about their habitat or life history requirements. Copyright ?? 2006 Magnolia Press.

  20. A new occurrence of Anodontites tenebricosus (Bivalvia: Mycetopodidae) in the Sapucaí river basin, São Paulo, Brazil: environmental and conchological aspects.

    PubMed

    Troncon, E K; Avelar, W E P

    2011-08-01

    The aim of this work was to register the occurrence of Anodontites tenebricosus (Bivalvia: Mycetopodidae) in the Sapucaí river basin, municipality of São Joaquim da Barra, São Paulo state, Brazil, associating its occurrence to the environment in which they are found, besides providing conchological data to contribute to the identification of the species. Fifty one specimens of Anodontites tenebricosus were studied regarding their conchological and morphometrical aspects. Strong correlations were found between the morphometric variables, the correlation between 'length and height of the shell' being the most significant. The characteristics of the shells of A. tenebricosus found in the Sapucaí river basin resemble the descriptions of the species found in the literature; therefore, we are able to expand the area of occurrence of the species for the state of São Paulo. PMID:21881786

  1. The complete mitochondrial genome of the grand jackknife clam, Solen grandis (Bivalvia: Solenidae): a novel gene order and unusual non-coding region.

    PubMed

    Yuan, Yang; Li, Qi; Kong, Lingfeng; Yu, Hong

    2012-02-01

    Molluscs in general, and bivalves in particular, exhibit an extraordinary degree of mitochondrial gene order variation when compared with other metazoans. The complete mitochondrial genome of Solen grandis (Bivalvia: Solenidae) was determined using long-PCR and genome walking techniques. The entire mitochondrial genome sequence of S. grandis is 16,784 bp in length, and contains 36 genes including 12 protein-coding genes (atp8 is absent), 2 ribosomal RNAs, and 22 tRNAs. All genes are encoded on the same strand. Compared with other species, it bears a novel gene order. Besides these, we find a peculiar non-coding region of 435 bp with a microsatellite-like (TA)(12) element, poly-structures and many hairpin structures. In contrast to the available heterodont mitochondrial genomes from GenBank, the complete mtDNA of S. grandis has the shortest cox3 gene, and the longest atp6, nad4, nad5 genes. PMID:21598108

  2. Phylogenetic and morphometric analyses reveal ecophenotypic plasticity in freshwater mussels Obovaria jacksoniana and Villosa arkansasensis (Bivalvia: Unionidae)

    PubMed Central

    Inoue, Kentaro; Hayes, David M; Harris, John L; Christian, Alan D

    2013-01-01

    Abstract Freshwater mollusk shell morphology exhibits clinal variation along a stream continuum that has been termed the Law of Stream Distribution. We analyzed phylogenetic relationships and morphological similarity of two freshwater mussels (Bivalvia: Unionidae), Obovaria jacksoniana and Villosa arkansasensis, throughout their ranges. The objectives were to investigate phylogenetic structure and evolutionary divergence of O. jacksoniana and V. arkansasensis and morphological similarity between the two species. Our analyses were the first explicit tests of phenotypic plasticity in shell morphologies using a combination of genetics and morphometrics. We conducted phylogenetic analyses of mitochondrial DNA (1416 bp; two genes) and morphometric analyses for 135 individuals of O. jacksoniana and V. arkansasensis from 12 streams. We examined correlations among genetic, morphological, and spatial distances using Mantel tests. Molecular phylogenetic analyses revealed a monophyletic relationship between O. jacksoniana and V. arkansasensis. Within this O. jacksoniana/V. arkansasensis complex, five distinct clades corresponding to drainage patterns showed high genetic divergence. Morphometric analysis revealed relative differences in shell morphologies between the two currently recognized species. We conclude that morphological differences between the two species are caused by ecophenotypic plasticity. A series of Mantel tests showed regional and local genetic isolation by distance. We observed clear positive correlations between morphological and geographic distances within a single drainage. We did not observe correlations between genetic and morphological distances. Phylogenetic analyses suggest O. jacksoniana and V. arkansasensis are synonomous and most closely related to a clade composed of O. retusa, O. subrotunda, and O. unicolor. Therefore, the synonomous O. jacksoniana and V. arkansasensis should be recognized as Obovaria arkansasensis (Lea 1862) n

  3. The complete mitochondrial genome of the golden mussel Limnoperna fortunei and comparative mitogenomics of Mytilidae.

    PubMed

    Uliano-Silva, Marcela; Americo, Juliana Alves; Costa, Igor; Schomaker-Bastos, Alex; de Freitas Rebelo, Mauro; Prosdocimi, Francisco

    2016-02-15

    Here we describe the mitochondrial genome of the golden mussel Limnoperna fortunei, an Asian bivalve which has become one of the most aggressive invasive species in Japan and South America. The mitochondrial genome of L. fortunei does not present conserved gene arrangement when compared to the other Mytilidae species suggesting a high degree of gene recombination in the mitochondria of this clade. In addition, the golden mussel mitogenome encodes two copies of tRNA(Lys) and presents a putative pseudogene for the atp8 gene sequence that encodes a 27 amino acid peptide containing an in-frame stop codon. The presence of this pseudogene raises the question as to whether atp8 is encoded in some bivalve mitochondrial genomes or not. The phylogenetic analysis of all complete mitochondrial genomes available from Mytilidae mussels confirmed the close evolutionary relationships among bivalves from the genus Mytilys and placed L. fortunei coming from a more ancestral branch on the family. The supermatrix phylogeny described used the concatenation of all 12 genes from the mitochondria and disputed the monophyly of the genus Perna, as Perna perna was shown to be more closely related to Brachidontes exustus than to Perna viridis. The comparative analysis of mitogenome synteny also confirmed the polyphyly of the genus Perna. The complete and annotated mitogenome has been published in GenBank under the accession number KP756905. PMID:26639990

  4. Persistent Contamination of Octopuses and Mussels with Lipophilic Shellfish Toxins during Spring Dinophysis Blooms in a Subtropical Estuary

    PubMed Central

    Mafra, Luiz L.; Lopes, Daiana; Bonilauri, Vanessa C.; Uchida, Hajime; Suzuki, Toshiyuki

    2015-01-01

    This study investigates the occurrence of diarrhetic shellfish toxins (DSTs) and their producing phytoplankton species in southern Brazil, as well as the potential for toxin accumulation in co-occurring mussels (Perna perna) and octopuses (Octopus vulgaris). During the spring in 2012 and 2013, cells of Dinophysis acuminata complex were always present, sometimes at relatively high abundances (max. 1143 cells L−1), likely the main source of okadaic acid (OA) in the plankton (max. 34 ng L−1). Dinophysis caudata occurred at lower cell densities in 2013 when the lipophilic toxins pectenotoxin-2 (PTX-2) and PTX-2 seco acid were detected in plankton and mussel samples. Here, we report for the first time the accumulation of DSTs in octopuses, probably linked to the consumption of contaminated bivalves. Perna perna mussels were consistently contaminated with different DSTs (max. 42 µg kg−1), and all octopuses analyzed (n = 5) accumulated OA in different organs/tissues: digestive glands (DGs) > arms > gills > kidneys > stomach + intestine. Additionally, similar concentrations of 7-O-palmytoyl OA and 7-O-palmytoly dinophysistoxin-1 (DTX-1) were frequently detected in the hepatopancreas of P. perna and DGs of O. vulgaris. Therefore, octopuses can be considered a potential vector of DSTs to both humans and top predators such as marine mammals. PMID:26096277

  5. Persistent Contamination of Octopuses and Mussels with Lipophilic Shellfish Toxins during Spring Dinophysis Blooms in a Subtropical Estuary.

    PubMed

    Mafra, Luiz L; Lopes, Daiana; Bonilauri, Vanessa C; Uchida, Hajime; Suzuki, Toshiyuki

    2015-06-01

    This study investigates the occurrence of diarrhetic shellfish toxins (DSTs) and their producing phytoplankton species in southern Brazil, as well as the potential for toxin accumulation in co-occurring mussels (Perna perna) and octopuses (Octopus vulgaris). During the spring in 2012 and 2013, cells of Dinophysis acuminata complex were always present, sometimes at relatively high abundances (max. 1143 cells L-1), likely the main source of okadaic acid (OA) in the plankton (max. 34 ng L-1). Dinophysis caudata occurred at lower cell densities in 2013 when the lipophilic toxins pectenotoxin-2 (PTX-2) and PTX-2 seco acid were detected in plankton and mussel samples. Here, we report for the first time the accumulation of DSTs in octopuses, probably linked to the consumption of contaminated bivalves. Perna perna mussels were consistently contaminated with different DSTs (max. 42 µg kg-1), and all octopuses analyzed (n = 5) accumulated OA in different organs/tissues: digestive glands (DGs) > arms > gills > kidneys > stomach + intestine. Additionally, similar concentrations of 7-O-palmytoyl OA and 7-O-palmytoly dinophysistoxin-1 (DTX-1) were frequently detected in the hepatopancreas of P. perna and DGs of O. vulgaris. Therefore, octopuses can be considered a potential vector of DSTs to both humans and top predators such as marine mammals. PMID:26096277

  6. Complete mitochondrial genome of Coelomactra antiquata (Mollusca: Bivalvia): The first representative from the family Mactridae with novel gene order and unusual tandem repeats.

    PubMed

    Meng, Xueping; Zhao, Nana; Shen, Xin; Hao, Jue; Liang, Meng; Zhu, Xiaolin; Cheng, Hanliang; Yan, Binlun; Liu, Zhaopu

    2012-06-01

    The complete mitochondrial genome plays an important role in the accurate inference of phylogenetic relationships among metazoans. Mactridae, also known as trough shells or duck clams, is an important family of marine bivalve clams in the order Veneroida. Here we present the complete mitochondrial genome sequence of the Xishishe Coelomactra antiquata (Mollusca: Bivalvia), which is the first representative from the family Mactridae. The mitochondrial genome of C. antiquata is of 17,384bp in length, and encodes 35 genes, including 12 protein-coding, 21 transfer RNA, and 2 ribosomal RNA genes. Compared with the typical gene content of animal mitochondrial genomes, atp8 and tRNAS(2) are missing. Gene order of the mitochondrial genome of C. antiquata is unique compared with others from Veneroida. In the mitochondrial genome of the C. antiquata, a total of 2189bp of non-coding nucleotides are scattered among 26 non-coding regions. The largest non-coding region contains one section of tandem repeats (99 bp×11), which is the second largest tandem repeats found in the mitochondrial genomes from Veneroida. The phylogenetic trees based on mitochondrial genomes support the monophyly of Veneridae and Lucinidae, and the relationship at the family level: ((Veneridae+Mactridae)+(Cardiidae+Solecurtidae))+Lucinidae. The phylogenetic result is consistent with the morphological classification. Meanwhile, bootstrap values are very high (BP=94-100), suggesting that the evolutionary relationship based on mitochondrial genomes is very reliable. PMID:22381378

  7. A new monorchiid cercaria (Digenea) parasitising the purple clam Amiantis purpurata (Bivalvia: Veneridae) in the Southwest Atlantic Ocean, with notes on its gonadal effect.

    PubMed

    Cremont, F; Kroeck, M A; Martorelli, S R

    2001-01-01

    An unnamed microcercous cercaria (Digenea: Monorchiidae), a parasite of Amiantis purpurata (Lamarck, 1818) (Bivalvia: Veneridae) and its corresponding metacercaria from the province of Buenos Aires and the Patagonian coast of the Southwest Atlantic Ocean, are described. The cercaria described in this paper differs from the three other monorchiid microcercous cercariae, i.e., Lasiotocus minutus (Manter, 1931), Lasiotocus elongatus (Manter, 1931), and Cercaria caribbea XXXVI Cable, 1956, mainly because of the extension of the excretory vesicle and the location of the ventral sucker. Cercariae artificially extracted from sporocysts encyst in a dish and form metacercariae enveloped by a gelatinous sac with two prolongations, which are used to adhere to the substratum. The monorchiid described in this paper has a life cycle similar to those of L. minutus and L. elongatus, although the adult stage of the present species is still unknown. Their larvae are similar in morphology and have venerid clams as their first hosts. The presence of a monorchiid larva is reported for the first time in the Southern Hemisphere. Its monthly prevalence rates, ranging from 0 to 25% (mean: 8.3%), are given from the Patagonian coast. The infection seems to cause castration as it was observed that during March through to May, when most gametes were produced in uninfected individuals, 81% of the infected individuals did not produce gametes. PMID:11699657

  8. Existence and Uniqueness of Maximal Regular Flows for Non-smooth Vector Fields

    NASA Astrophysics Data System (ADS)

    Ambrosio, Luigi; Colombo, Maria; Figalli, Alessio

    2015-11-01

    In this paper we provide a complete analogy between the Cauchy-Lipschitz and the DiPerna-Lions theories for ODE's, by developing a local version of the DiPerna-Lions theory. More precisely, we prove the existence and uniqueness of a maximal regular flow for the DiPerna-Lions theory using only local regularity and summability assumptions on the vector field, in analogy with the classical theory, which uses only local regularity assumptions. We also study the behaviour of the ODE trajectories before the maximal existence time. Unlike the Cauchy-Lipschitz theory, this behaviour crucially depends on the nature of the bounds imposed on the spatial divergence of the vector field. In particular, a global assumption on the divergence is needed to obtain a proper blow-up of the trajectories.

  9. Microplastic contamination in natural mussel beds from a Brazilian urbanized coastal region: Rapid evaluation through bioassessment.

    PubMed

    Santana, M F M; Ascer, L G; Custódio, M R; Moreira, F T; Turra, A

    2016-05-15

    Microplastic pollution (particles <5mm) is a widespread marine threat and a trigger for biological effects, especially if ingested. The mussel Perna perna, an important food resource, was used as bioindicator to investigate the presence of microplastic pollution on Santos estuary, the most urbanized area of the coast of São Paulo State, Brazil. A simple and rapid assessment showed that 75% of sampled mussels had ingested microplastics, an issue of human and environmental concern. All sampling points had contaminated mussels and this contamination had no clear pattern of distribution along the estuary. This was the first time that microplastic bioavailability was assessed in nature for the southern hemisphere and that wild P. perna was found contaminated with this pollutant. This is an important issue that should be better assessed due to an increase in seafood consumption and culture in Brazil and worldwide. PMID:26980138

  10. Cheating the Locals: Invasive Mussels Steal and Benefit from the Cooling Effect of Indigenous Mussels

    PubMed Central

    Lathlean, Justin A.; Seuront, Laurent; McQuaid, Christopher D.; Ng, Terence P. T.; Zardi, Gerardo I.; Nicastro, Katy R.

    2016-01-01

    The indigenous South African mussel Perna perna gapes during periods of aerial exposure to maintain aerobic respiration. This behaviour has no effect on the body temperatures of isolated individuals, but when surrounded by conspecifics, beneficial cooling effects of gaping emerge. It is uncertain, however, whether the presence of the invasive mussel Mytilus galloprovincialis limits the ability of P. perna for collective thermoregulation. We investigated whether varying densities of P. perna and M. galloprovincialis influences the thermal properties of both natural and artificial mussel beds during periods of emersion. Using infrared thermography, body temperatures of P. perna within mixed artificial beds were shown to increase faster and reach higher temperatures than individuals in conspecific beds, indicating that the presence of M. galloprovincialis limits the group cooling effects of gaping. In contrast, body temperatures of M. galloprovincialis within mixed artificial mussel beds increased slower and exhibited lower temperatures than for individuals in beds comprised entirely of M. galloprovincialis. Interestingly, differences in bed temperatures and heating rates were largely dependent on the size of mussels, with beds comprised of larger individuals experiencing less thermal stress irrespective of species composition. The small-scale patterns of thermal stress detected within manipulated beds were not observed within naturally occurring mixed mussel beds. We propose that small-scale differences in topography, size-structure, mussel bed size and the presence of organisms encrusting the mussel shells mask the effects of gaping behaviour within natural mussel beds. Nevertheless, the results from our manipulative experiment indicate that the invasive species M. galloprovincialis steals thermal properties as well as resources from the indigenous mussel P. perna. This may have significant implications for predicting how the co-existence of these two species may

  11. Cheating the Locals: Invasive Mussels Steal and Benefit from the Cooling Effect of Indigenous Mussels.

    PubMed

    Lathlean, Justin A; Seuront, Laurent; McQuaid, Christopher D; Ng, Terence P T; Zardi, Gerardo I; Nicastro, Katy R

    2016-01-01

    The indigenous South African mussel Perna perna gapes during periods of aerial exposure to maintain aerobic respiration. This behaviour has no effect on the body temperatures of isolated individuals, but when surrounded by conspecifics, beneficial cooling effects of gaping emerge. It is uncertain, however, whether the presence of the invasive mussel Mytilus galloprovincialis limits the ability of P. perna for collective thermoregulation. We investigated whether varying densities of P. perna and M. galloprovincialis influences the thermal properties of both natural and artificial mussel beds during periods of emersion. Using infrared thermography, body temperatures of P. perna within mixed artificial beds were shown to increase faster and reach higher temperatures than individuals in conspecific beds, indicating that the presence of M. galloprovincialis limits the group cooling effects of gaping. In contrast, body temperatures of M. galloprovincialis within mixed artificial mussel beds increased slower and exhibited lower temperatures than for individuals in beds comprised entirely of M. galloprovincialis. Interestingly, differences in bed temperatures and heating rates were largely dependent on the size of mussels, with beds comprised of larger individuals experiencing less thermal stress irrespective of species composition. The small-scale patterns of thermal stress detected within manipulated beds were not observed within naturally occurring mixed mussel beds. We propose that small-scale differences in topography, size-structure, mussel bed size and the presence of organisms encrusting the mussel shells mask the effects of gaping behaviour within natural mussel beds. Nevertheless, the results from our manipulative experiment indicate that the invasive species M. galloprovincialis steals thermal properties as well as resources from the indigenous mussel P. perna. This may have significant implications for predicting how the co-existence of these two species may

  12. The linked units of 5S rDNA and U1 snDNA of razor shells (Mollusca: Bivalvia: Pharidae).

    PubMed

    Vierna, J; Jensen, K T; Martínez-Lage, A; González-Tizón, A M

    2011-08-01

    The linkage between 5S ribosomal DNA and other multigene families has been detected in many eukaryote lineages, but whether it provides any selective advantage remains unclear. In this work, we report the occurrence of linked units of 5S ribosomal DNA (5S rDNA) and U1 small nuclear DNA (U1 snDNA) in 10 razor shell species (Mollusca: Bivalvia: Pharidae) from four different genera. We obtained several clones containing partial or complete repeats of both multigene families in which both types of genes displayed the same orientation. We provide a comprehensive collection of razor shell 5S rDNA clones, both with linked and nonlinked organisation, and the first bivalve U1 snDNA sequences. We predicted the secondary structures and characterised the upstream and downstream conserved elements, including a region at -25 nucleotides from both 5S rDNA and U1 snDNA transcription start sites. The analysis of 5S rDNA showed that some nontranscribed spacers (NTSs) are more closely related to NTSs from other species (and genera) than to NTSs from the species they were retrieved from, suggesting birth-and-death evolution and ancestral polymorphism. Nucleotide conservation within the functional regions suggests the involvement of purifying selection, unequal crossing-overs and gene conversions. Taking into account this and other studies, we discuss the possible mechanisms by which both multigene families could have become linked in the Pharidae lineage. The reason why 5S rDNA is often found linked to other multigene families seems to be the result of stochastic processes within genomes in which its high copy number is determinant. PMID:21364693

  13. Scorched mussels (BIVALVIA: MYTILIDAE: BRACHIDONTINAE) from the temperate coasts of South America: phylogenetic relationships, trans-Pacific connections and the footprints of Quaternary glaciations.

    PubMed

    Trovant, Berenice; Orensanz, J M Lobo; Ruzzante, Daniel E; Stotz, Wolfgang; Basso, Néstor G

    2015-01-01

    This study addresses aspects of the phylogeny and phylogeography of scorched mussels (BIVALVIA: MYTILIDAE: BRACHIDONTINAE) from southern South America (Argentina and Chile), as well as their ecophylogenetic implications. Relationships were inferred from sequences of two nuclear (28S and 18S) and one mitochondrial (COI) genes, using Bayesian and maximum likelihood analyses. Our results indicate that the monophyletic BRACHIDONTINAE include three well supported clades: [i] Brachidontes Swainson (=Hormomya Mörch), [ii] Ischadium Jukes-Browne+Geukensia van de Poel, and [iii] Austromytilus Laseron+Mytilisepta Habe (usually considered a member of the SEPTIFERINAE)+Perumytilus Olsson. Species of clade [iii] are distributed along the temperate coasts of the Pacific Ocean. Available evidence supports divergence between Austromytilus (Australia) and Perumytilus (South American) following the breakup of Australian, Antarctic and South American shelves. Four brachidontins occur in southern South America: Brachidontes rodriguezii (d'Orbigny), B. granulatus (Hanley), and two genetically distinct clades of Perumytilus. The latter are confined to the Chile-Peru (North Clade) and Magellanic (South Clade) Biogeographic Provinces, respectively warm- and cold-temperate. The South Clade is the only brachidontin restricted to cold-temperate waters. Biogeographic considerations and the fossil record prompted the hypothesis that the South Clade originated from the North Clade by incipient peripatric differentiation, followed by isolation during the Quaternary glaciations, genetic differentiation in the non-glaciated coasts of eastern Patagonia, back-expansion over southern Chile following post-LGM de-glaciation, and development of a secondary contact zone between the two clades in south-central Chile. Evidence of upper Pleistocene expansion of the South Clade parallels similar results on other organisms that have colonized coastal ecosystems from eastern Patagonia since the LGM

  14. Impact of zebra and quagga mussels (Dreissena spp.) on freshwater unionids (Bivalvia: Unionidae) in the Detroit River of the Great Lakes

    USGS Publications Warehouse

    Schloesser, D.W.; Kovalak, W.P.; Longton, G.D.; Ohnesorg, K.L.; Smithee, R.D.

    1998-01-01

    To assess the impact of zebra and quagga mussel (Dreissena spp.) infestation on unionids, unionids (Bivalvia: Unionidae) were sampled in the Detroit River in 1982-1983, before mussels invaded the river, and in 1992 and 1994, after mussels invaded the river. Live unionids at four stations along the southeastern shore accounted for 97% (20 species) of all shells collected in 1982-1983, whereas live unionids accounted for only 10% (13 species) in 1992. A similar decline in live unionids occurred at nine stations along the northwestern shore, except the decline occurred over the three sampling periods: in 1982-83, 84% (22 species) were live; in 1992, 65% (26 species) were live; and, in 1994, only 3% (13 species) were live. The difference in time to near-total mortality of unionids along the southeastern and northwestern shores is attributed to differences in the time of invasion and abundance of zebra mussel veligers in distinct water masses emanating from Lake St. Clair located immediately upstream of the Detroit River. Although individuals of all species of all unionid subfamilies declined between 1982 and 1992/1994, members of the subfamilies Anodontinae and Lampsilinae declined more than Ambleminae. Between 1986 and 1992/1994, five Anodontinae, three Lampsilinae and 0 Ambleminae species have been extirpated from the river due to dreissenid mussel infestation. Numbers of individuals of commonly found species declined more than numbers of individuals of uncommonly found species. However, the number of uncommon species declined 47% (17 to 9) along both the southeastern and northwestern shores, whereas common species remained the same (3 species) along the southeastern shore and declined only 40% (5 to 3 species) along the northwestern shore. This study, and others, suggest that high mortality of unionids can occur between 4 and 6 yr after initial invasion by dreissenids or up to 8 yr depending on water current patterns. Infestation-induced mortality of unionids in the

  15. TOXOPLASMA GONDII ISOLATES FROM FREE-RANGE CHICKENS FORM THE NORTHEAST REGION OF BRAZIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 152 free-range chickens (Gallus domesticus) from 22 municipalities in 7 northeastern states (Perna...

  16. Access to College: A Reconsideration of the National Education Longitudinal Study (NELS)

    ERIC Educational Resources Information Center

    Daun-Barnett, Nathan J.

    2013-01-01

    Student's access to college is influenced both by their level of academic preparation to do college-level work and the cost of participating in postsecondary education--on this point researchers and policy makers seem to agree (Perna, 2006). The relative importance of each, however, is very much a subject of disagreement and that debate has…

  17. Mercury concentrations in the coastal marine food web along the Senegalese coast.

    PubMed

    Diop, Mamadou; Amara, Rachid

    2016-06-01

    This paper presents the results of seasonal (wet and dry seasons) and spatial (five sites) variation of mercury concentration in seven marine organisms representative for shallow Senegalese coastal waters and including species of commercial importance. Total mercury levels were recorded in the green algae (Ulva lactuca); the brown mussel (Perna perna); the Caramote prawn (Penaeus kerathurus); and in the liver and muscles of the following fish: Solea senegalensis, Mugil cephalus, Saratherondon melanotheron, and Sardinella aurita. The total selenium (Se) contents were determined only in the edible part of Perna perna, Penaeus kerathurus and in the muscles of Sardinella aurita and Solea senegalensis. Hg concentration in fish species was higher in liver compared to the muscle. Between species differences in Hg, concentrations were recorded with the highest concentration found in fish and the lowest in algae. The spatiotemporal study showed that there was no clear seasonal pattern in Hg concentrations in biota, but spatial differences existed with highest concentrations in sites located near important anthropogenic pressure. For shrimp, mussel, and the muscles of sardine and sole, Hg concentrations were below the health safety limits for human consumption as defined by the European Union. The Se/Hg molar ratio was always higher than one whatever the species or location suggesting a protection of Se against Hg potential adverse effect. PMID:26961529

  18. Mexican Americans Acquiring Bachelor's Degrees: Whose Opportunity?

    ERIC Educational Resources Information Center

    Evans, Carol

    2009-01-01

    This study offers a small, highly contextualized counter-example to several recent large-scale analyses depicting Latino underachievement in higher education (R. Fry, 2002; J. Immerwahr, 2003; S. Miller & E. Garcia, 2004; W. Swail, A. Cabrera, & C. Lee, 2004; W. S. Swail, K. E. Redd, & L. W. Perna, 2003). The purpose is to analyze results from a…

  19. Ensuring That Professors Who Enhance the University Earn Tenure and Promotion

    ERIC Educational Resources Information Center

    Gentry, Ruben

    2013-01-01

    Tenure provides professors with a unique level of job security and utmost respect in the academy (Shea, 2002). Receiving tenure and progressing through the academic ranks are among the most visible and valued accomplishments for college and university faculty (Perna, 2001). Faculty who achieve excellence in teaching, research, and service readily…

  20. Field Measurements Indicate Unexpected, Serious Underestimation of Mussel Heart Rates and Thermal Tolerance by Laboratory Studies

    PubMed Central

    Tagliarolo, Morgana; McQuaid, Christopher D.

    2016-01-01

    Attempts to predict the response of species to long-term environmental change are generally based on extrapolations from laboratory experiments that inevitably simplify the complex interacting effects that occur in the field. We recorded heart rates of two genetic lineages of the brown mussel Perna perna over a full tidal cycle in-situ at two different sites in order to evaluate the cardiac responses of the two genetic lineages present on the South African coast to temperature and the immersion/emersion cycle. “Robomussel” temperature loggers were used to monitor thermal conditions at the two sites over one year. Comparison with live animals showed that robomussels provided a good estimate of mussel body temperatures. A significant difference in estimated body temperatures was observed between the sites and the results showed that, under natural conditions, temperatures regularly approach or exceed the thermal limits of P. perna identified in the laboratory. The two P. perna lineages showed similar tidal and diel patterns of heart rate, with higher cardiac activity during daytime immersion and minimal values during daytime emersion. Comparison of the heart rates measured in the field with data previously measured in the laboratory indicates that laboratory results seriously underestimate heart rate activity, by as much as 75%, especially during immersion. Unexpectedly, field estimates of body temperatures indicated an ability to tolerate temperatures considered lethal on the basis of laboratory measurements. This suggests that the interaction of abiotic conditions in the field does not necessarily raise vulnerability to high temperatures. PMID:26840775

  1. Flows for non-smooth vector fields with subexponentially integrable divergence

    NASA Astrophysics Data System (ADS)

    Clop, Albert; Jiang, Renjin; Mateu, Joan; Orobitg, Joan

    2016-07-01

    In this paper, we study flows associated to Sobolev vector fields with subexponentially integrable divergence. Our approach is based on the transport equation following DiPerna-Lions [17]. A key ingredient is to use a quantitative estimate of solutions to the Cauchy problem of transport equation to obtain the regularity of density functions.

  2. Predictors of Graduate Enrollment in Hard and Soft Academic Disciplines and the Impact of Sex and Ethnicity

    ERIC Educational Resources Information Center

    McAnulty, Katheryn G.

    2009-01-01

    Given the underrepresentation of research on graduate college choice, particularly that which utilizes a national sample of students enrolled in a wide range of institutions of higher education across the United States, this study aims to contribute significantly to the field of graduate access and admissions. Building on the work of Perna (2004)…

  3. Graduate Education Attainment and Salary: An Examination of Institutional Type, Major Choice, Gender, Race/Ethnicity, Parental Education and Work Experience Differences

    ERIC Educational Resources Information Center

    Bell, Chandra M.

    2010-01-01

    This study investigated two major sources of influence (institution and individual characteristics) on the earnings of graduate degree recipients. These factors have been shown in previous research to influence the initial earnings of graduates at the undergraduate level. This research seeks to build on previous studies by Perna (2003, 2005) that…

  4. Making the Grade: The Importance of Academic Enablers in the Elementary School Counseling Program

    ERIC Educational Resources Information Center

    Barna, Jennifer S.; Brott, Pamelia E.

    2014-01-01

    Elementary school counselors can support academic achievement by connecting their comprehensive programs to increasing academic competence. One valuable framework focuses on academic enablers, which are identified as interpersonal skills, motivation, engagement, and study skills (DiPerna, 2004). In this article, the authors (a) discuss the…

  5. PERFORMANCE TESTING OF THE DIPERNA SWEEPER

    EPA Science Inventory

    The DiPerna Sweeper, a partial-vacuum oil skimmer, was tested in a two-week test program conducted at the U.S. Environmental Test Tank (OHMSETT) in Leonardo, New Jersey. Forty-three oil recovery tests were run. The object of the program was to establish a range of best performanc...

  6. Field Measurements Indicate Unexpected, Serious Underestimation of Mussel Heart Rates and Thermal Tolerance by Laboratory Studies.

    PubMed

    Tagliarolo, Morgana; McQuaid, Christopher D

    2016-01-01

    Attempts to predict the response of species to long-term environmental change are generally based on extrapolations from laboratory experiments that inevitably simplify the complex interacting effects that occur in the field. We recorded heart rates of two genetic lineages of the brown mussel Perna perna over a full tidal cycle in-situ at two different sites in order to evaluate the cardiac responses of the two genetic lineages present on the South African coast to temperature and the immersion/emersion cycle. "Robomussel" temperature loggers were used to monitor thermal conditions at the two sites over one year. Comparison with live animals showed that robomussels provided a good estimate of mussel body temperatures. A significant difference in estimated body temperatures was observed between the sites and the results showed that, under natural conditions, temperatures regularly approach or exceed the thermal limits of P. perna identified in the laboratory. The two P. perna lineages showed similar tidal and diel patterns of heart rate, with higher cardiac activity during daytime immersion and minimal values during daytime emersion. Comparison of the heart rates measured in the field with data previously measured in the laboratory indicates that laboratory results seriously underestimate heart rate activity, by as much as 75%, especially during immersion. Unexpectedly, field estimates of body temperatures indicated an ability to tolerate temperatures considered lethal on the basis of laboratory measurements. This suggests that the interaction of abiotic conditions in the field does not necessarily raise vulnerability to high temperatures. PMID:26840775

  7. How Four-Year Colleges and Universities Organize Themselves to Promote Student Persistence: The Emerging National Picture

    ERIC Educational Resources Information Center

    College Board Advocacy & Policy Center, 2011

    2011-01-01

    As leading measures of student success and institutional quality, persistence and graduation rates are intensely debated at education conferences, institutional meetings and legislative sessions (Adelman, 1999; American Association of State Colleges and Universities [AASCU], 2002; Gold & Albert, 2006; Perna & Thomas, 2006; Tinto & Pusser, 2006;…

  8. Be Bold ... Be Enrollment Rich

    ERIC Educational Resources Information Center

    Perna, Mark C.

    2004-01-01

    In this paper, marketing specialist Mark Perna offers advice on how career and technical schools can market themselves and their programs. To become "enrollment rich," he suggests the following: (1) develop a brand plan--something that separates your organization from competitors in the mind of the community; (2) deliver the message--the community…

  9. The College Choice Process of Four Students from Rural Appalachian Kentucky

    ERIC Educational Resources Information Center

    Harris, Kristen L.

    2013-01-01

    This study examined the extent to which the college choice process of four students from one high school in rural Appalachian Kentucky aligned with Perna's (2006; 2010) nested process model of college choice. I used qualitative case study methodology and inductive analysis to describe how four high-academic achieving students of varying family…

  10. Examining Early Literacy Skill Differences among Children in Head Start via Latent Profile Analysis

    ERIC Educational Resources Information Center

    Norwalk, Kate E.; DiPerna, James C.; Lei, Pui-wa; Wu, Qiong

    2012-01-01

    The purpose of the present study was to determine whether there are systematic differences in literacy skills among children from less-advantaged households, using latent profile analysis. Early reading skills were measured using the Early Arithmetic, Reading, and Learning Indicators (EARLI; DiPerna, Morgan, & Lei, 2007) literacy tasks.…

  11. Screening for Early Learning Problems within an Urban Population: The Brief Academic Competence Evaluation Screening System

    ERIC Educational Resources Information Center

    Kettler, Ryan J.

    2007-01-01

    The Brief Academic Competence Evaluation Screening System (BACESS; Elliott, DiPerna, & Huai, 2003) is a multi-phase instrument designed to assist educators in the identification of students who are likely to experience early learning problems. The BACESS was used in eight elementary classrooms (n=71) in southern California. Each phase of the…

  12. Academic Enablers and Student Achievement: Implications for Assessment and Intervention Services in the Schools

    ERIC Educational Resources Information Center

    DiPerna, James Clyde

    2006-01-01

    Academic enablers have been defined as attitudes and behaviors that facilitate students' participation in, and benefit from, academic instruction in the classroom (J.C. DiPerna & S.N. Elliott, 2000). The purpose of this article is to provide practitioners with an overview of specific academic enablers (motivation, study skills, engagement, and…

  13. Increasing Access to College: Extending Possibilities for All Students. SUNY Series, Frontiers in Education.

    ERIC Educational Resources Information Center

    Tierney, William G., Ed.; Hagedorn, Linda Serra, Ed.

    This collection of papers examines pre-college enrichment programs that offer a specific remedy to the problem of low income and underrepresented students' access to higher education. The 10 papers are: (1) "Pre-College Outreach Programs: A National Perspective" (Watson Scott Swail and Laura W. Perna); (2) "The Relationship between Urbanicity and…

  14. Wider sampling reveals a non-sister relationship for geographically contiguous lineages of a marine mussel

    PubMed Central

    Cunha, Regina L; Nicastro, Katy R; Costa, Joana; McQuaid, Christopher D; Serrão, Ester A; Zardi, Gerardo I

    2014-01-01

    The accuracy of phylogenetic inference can be significantly improved by the addition of more taxa and by increasing the spatial coverage of sampling. In previous studies, the brown mussel Perna perna showed a sister–lineage relationship between eastern and western individuals contiguously distributed along the South African coastline. We used mitochondrial (COI) and nuclear (ITS) sequence data to further analyze phylogeographic patterns within P. perna. Significant expansion of the geographical coverage revealed an unexpected pattern. The western South African lineage shared the most recent common ancestor (MRCA) with specimens from Angola, Venezuela, and Namibia, whereas eastern South African specimens and Mozambique grouped together, indicating a non-sister relationship for the two South African lineages. Two plausible biogeographic scenarios to explain their origin were both supported by the hypotheses-testing analysis. One includes an Indo-Pacific origin for P. perna, dispersal into the Mediterranean and Atlantic through the Tethys seaway, followed by recent secondary contact after southward expansion of the western and eastern South African lineages. The other scenario (Out of South Africa) suggests an ancient vicariant divergence of the two lineages followed by their northward expansion. Nevertheless, the “Out of South Africa” hypothesis would require a more ancient divergence between the two lineages. Instead, our estimates indicated that they diverged very recently (310 kyr), providing a better support for an Indo-Pacific origin of the two South African lineages. The arrival of the MRCA of P. perna in Brazil was estimated at 10 [0–40] kyr. Thus, the hypothesis of a recent introduction in Brazil through hull fouling in wooden vessels involved in the transatlantic itineraries of the slave trade did not receive strong support, but given the range for this estimate, it could not be discarded. Wider geographic sampling of marine organisms shows that

  15. Wider sampling reveals a non-sister relationship for geographically contiguous lineages of a marine mussel.

    PubMed

    Cunha, Regina L; Nicastro, Katy R; Costa, Joana; McQuaid, Christopher D; Serrão, Ester A; Zardi, Gerardo I

    2014-06-01

    The accuracy of phylogenetic inference can be significantly improved by the addition of more taxa and by increasing the spatial coverage of sampling. In previous studies, the brown mussel Perna perna showed a sister-lineage relationship between eastern and western individuals contiguously distributed along the South African coastline. We used mitochondrial (COI) and nuclear (ITS) sequence data to further analyze phylogeographic patterns within P. perna. Significant expansion of the geographical coverage revealed an unexpected pattern. The western South African lineage shared the most recent common ancestor (MRCA) with specimens from Angola, Venezuela, and Namibia, whereas eastern South African specimens and Mozambique grouped together, indicating a non-sister relationship for the two South African lineages. Two plausible biogeographic scenarios to explain their origin were both supported by the hypotheses-testing analysis. One includes an Indo-Pacific origin for P. perna, dispersal into the Mediterranean and Atlantic through the Tethys seaway, followed by recent secondary contact after southward expansion of the western and eastern South African lineages. The other scenario (Out of South Africa) suggests an ancient vicariant divergence of the two lineages followed by their northward expansion. Nevertheless, the "Out of South Africa" hypothesis would require a more ancient divergence between the two lineages. Instead, our estimates indicated that they diverged very recently (310 kyr), providing a better support for an Indo-Pacific origin of the two South African lineages. The arrival of the MRCA of P. perna in Brazil was estimated at 10 [0-40] kyr. Thus, the hypothesis of a recent introduction in Brazil through hull fouling in wooden vessels involved in the transatlantic itineraries of the slave trade did not receive strong support, but given the range for this estimate, it could not be discarded. Wider geographic sampling of marine organisms shows that lineages

  16. Comparative Study of Various Immune Parameters in Three Bivalve Species during a Natural Bloom of Dinophysis acuminata in Santa Catarina Island, Brazil

    PubMed Central

    Mello, Danielle Ferraz; Proença, Luis Antonio de Oliveira; Barracco, Margherita Anna

    2010-01-01

    This study aimed to verify if Dinophysis acuminata natural blooms affected the immune system of three bivalves: the oyster, Crassostrea gigas, the mussel, Perna perna, and the clam, Anomalocardia brasiliana. Animals were obtained from a renowned mariculture farm in the southern bay of Santa Catarina Island during, and 30 days after (controls), an algal bloom. Various immunological parameters were assessed in the hemolymph of the animals: total and differential hemocyte counts, percentage of apoptotic hemocytes, protein concentration, hemagglutinating titer and phenoloxidase activity. The results showed that the mussel was the most affected species, with several altered immune parameters, whereas the immunological profile of clams and oysters was partially and completely unaffected, respectively. PMID:22069632

  17. A new species of Afropinnotheres Manning, 1993 (Crustacea, Brachyura, Pinnotheridae) from southwestern India, the first record of the genus from the Indian Ocean, with a review of the Pinnotheridae of India and adjacent seas.

    PubMed

    Ng, Peter K L; Kumar, Appukuttannair Biju

    2015-01-01

    A new species of pinnotherid crab of the genus Afropinnotheres Manning, 1993, is described from the brown mussel, Perna perna (Linnaeus, 1758), in southwestern India. This is the first record of the genus from the western Indian Ocean, the other four species been recorded from the eastern Atlantic. The new species can be distinguished from all congeners in  possessing a more rounded male carapace, form of the chela, relatively longer ambulatory legs which have no natatory setae, presence of dense pubescence on the male ambulatory legs, and the shape of the male and female telsons. The Indian Pinnotheridae is also reviewed and the taxonomy of the species reappraised. The taxonomy of Pinnaxodes Heller, 1865, and Holothuriophilus Nauck, 1880, is also discussed, in the context of their similarity to Afropinnotheres. PMID:25947734

  18. Metals and pesticides in commercial bivalve mollusc production areas in the North and South Bays, Santa Catarina (Brazil).

    PubMed

    de Souza, R V; Garbossa, L H P; Campos, C J A; Vianna, L F de N; Vanz, A; Rupp, G S

    2016-04-15

    Concentrations of heavy metals were quantified in mussels Perna perna and Pacific oysters Crassostrea gigas in 28 cultivation sites in the North and South Bays, SC (Brazil). Concentrations of pesticides were also quantified in these bivalve, water and sediment samples collected in 14 cultivation sites on four occasions in the period October 2012-October 2013. Pesticides were not detected in any of the mussel, oyster, water or sediment samples. The South Bay was found to be generally more contaminated with As while the North Bay showed higher concentrations of Ni. Concentrations of Pb and Cd were below the limit of detection of the method (0.5mg/kg) in all samples. Mussels accumulated more As and Ni than oysters, while the opposite was observed for Cu. Metal concentrations were below the maximum levels for foodstuffs specified in the Brazilian legislation. PMID:26897362

  19. Challenges associated with pre-border management of biofouling on oil rigs.

    PubMed

    Hopkins, Grant A; Forrest, Barrie M

    2010-11-01

    The potential for oil rigs to transport diverse, reef-like communities around the globe makes them high risk vectors for the inadvertent spread of non-indigenous species (NIS). This paper describes two case studies where a suite of pre-border management approaches was applied to semi-submersible drilling rigs. In the first case study, a drilling rig was defouled in-water prior to departure from New Zealand to Australia. Risk mitigation measures were successful in reducing biosecurity risks to the recipient region, but they resulted in the unintentional introduction of the non-indigenous brown mussel (Perna perna) to New Zealand when the rig was defouled in-water by divers. In the second case study, lessons learned from this high-profile incursion resulted in a more structured approach to pre-border management, and this serves as a useful template for future rig transfers. PMID:20696440

  20. [Ecophysiological adaptability of tropical water organisms to salinity changes].

    PubMed

    Chung, K S

    2001-03-01

    Physiological response of tropical organisms to salinity changes was studied for some marine, estuarine and freshwater fishes (Astyanax bimaculatus, Petenia karussii, Cyprinodon dearborni, and Oreochromis mossambicus), marine and freshwater crustaceans (Penaeus brasiliensis, Penaeus schmitti and Macrobrachium carcinus), and marine bivalves (Perna perna, Crassostrea rhizophorae, and Arca zebra) collected from Northeast Venezuela. They were acclimated for four weeks at various salinities, and (1) placed at high salinities to determine mean lethal salinity, (2) tested by increasing salinity 5@1000 per day to define upper lethal salinity tolerance limit, or (3) observed in a saline gradient tank to determine salinity preference. Acclimation level was the most significant factor. This phenomenon is important for tropical aquatic organisms in shallow waters, where they can adapt to high salinity during the dry season and cannot lose their acclimation level at low salinity during abrupt rain. For saline adaptation of tropical organisms, this behavior will contribute to their proliferation and distribution in fluctuating salinity environments. PMID:11795174

  1. Tolerance of five species of tropical marine mussels to continuous chlorination.

    PubMed

    Rajagopal, S; Venugopalan, V P; Van der Velde, G; Jenner, H A

    2003-05-01

    The paper examines the relative lethal and sublethal response of five important tropical marine mussels (Perna viridis, Perna perna, Brachidontes striatulus, Brachidontes variabilis and Modiolus philippinarum) to different chlorine concentrations varying from 0.25 to 15 mg l(-1). The mussels were observed to co-exist in the cooling water circuits of a coastal power station that adopted intermittent chlorination as a fouling control technique. The five mussel species showed, in response to chlorination, 100% mortality at significantly different exposure times, indicating significant species-specific variability in chlorine tolerance. For example, at 1 mg l(-1) residual chlorine, B. variabilis and P. viridis took 288 and 816 h, respectively, to achieve 100% mortality. The time taken for 100% mortality decreased with increasing chlorine residual concentration. The effect of mussel size (= mussel age) of P. viridis, P. perna, B. striatulus and M. philippinarum on mortality was significant between 1 and 5 mg l(-1) residual chlorine, with larger mussels showing greater resistance than smaller ones. All mussel species showed progressive reduction in physiological activities when chlorine residuals were increased from 0 to 1 mg l(-1). However, species-specific differences in the relative rate of physiological activities were observed. Accordingly, relative reduction in physiological activities in response to chlorination was the lowest in P. viridis and the highest in B. variabilis. The data clearly indicate significant differences in the lethal and sublethal responses of the five mussel species to chlorination. The results, therefore, suggest that for effective fouling control, chlorine treatment against mussels has to be employed judiciously, depending on the mussel species involved. PMID:12517421

  2. Toxic responses of bivalves to metal mixtures

    SciTech Connect

    Mathew, P.; Menon, N.R. )

    1992-02-01

    Although there is a growing body of information on the toxicity of individual heavy metals to economically important on the toxicity of individual heavy metals to economically important species of bivalves, literature on the lethal toxicity of metal mixtures to bivalves under controlled conditions is rather limited. In the present investigation the toxic effects of combinations of copper - mercury and copper - mercury and copper - cadmium at lethal levels of two marine bivalve species, Perna indica and Donax incarnatus, have been delineated.

  3. The Continuous Coagulation-FragmentationEquations with Diffusion

    NASA Astrophysics Data System (ADS)

    Laurençot, Philippe; Mischler, Stéphane

    Existence of global weak solutions to the continuous coagulation-fragmentation equations with diffusion is investigated when the kinetic coefficients satisfy a detailed balance condition or the coagulation coefficient enjoys a monotonicity condition. Our approach relies on weak and strong compactness methods in L1 in the spirit of the DiPerna-Lions theory for the Boltzmann equation. Under the detailed balance condition the large-time behaviour is also studied.

  4. Vesicomyidae (bivalvia): current taxonomy and distribution.

    PubMed

    Krylova, Elena M; Sahling, Heiko

    2010-01-01

    Vesicomyid bivalves are a consistent component of communities of sulphide-rich reducing environments distributed worldwide from 77 degrees N to 70 degrees S at depths from 100 to 9050 m. Up-to-now the taxonomy of the family has been uncertain. In this paper, the current state of vesicomyid taxonomy and distribution at the generic rank are considered. This survey is founded on a database including information both from literature sources and also unpublished data of the authors on all recent species of vesicomyids. We suggest that the Vesicomyidae is not a synonym of Kelliellidae, and is therefore a valid family name. We propose to divide the family Vesicomyidae into two subfamilies: Vesicomyinae and Pliocardiinae. The Vesicomyinae includes one genus, Vesicomya, which comprises small-sized bivalves characterized by non-reduced gut and the absence of subfilamental tissue in gills. Symbiosis with chemoautotrophic bacteria has, so far, not been proved for Vesicomya and the genus is not restricted to sulphide-rich reducing habitats. The subfamily Pliocardiinae currently contains about 15 genera with mostly medium or large body size, characterized by the presence of subfilamental tissue in the gills. The Pliocardiinae are highly specialized for sulphide-rich reducing environments, harbouring chemoautrophic bacteria in their gills. This is the first summary of the generic structure of the family Vesicomyidae that allow us to analyze the distribution of vesicomyids at the generic level. We recognize here five different distribution patterns that are related to the specific environmental demands. The general trends in the distribution patterns of the vesicomyids are an occurrence of the majority of genera in broad geographical ranges and the prevalence of near continental type of distribution. PMID:20376362

  5. Vesicomyidae (Bivalvia): Current Taxonomy and Distribution

    PubMed Central

    Krylova, Elena M.; Sahling, Heiko

    2010-01-01

    Vesicomyid bivalves are a consistent component of communities of sulphide-rich reducing environments distributed worldwide from 77° N to 70°S at depths from 100 to 9050 m. Up-to-now the taxonomy of the family has been uncertain. In this paper, the current state of vesicomyid taxonomy and distribution at the generic rank are considered. This survey is founded on a database including information both from literature sources and also unpublished data of the authors on all recent species of vesicomyids. We suggest that the Vesicomyidae is not a synonym of Kelliellidae, and is therefore a valid family name. We propose to divide the family Vesicomyidae into two subfamilies: Vesicomyinae and Pliocardiinae. The Vesicomyinae includes one genus, Vesicomya, which comprises small-sized bivalves characterized by non-reduced gut and the absence of subfilamental tissue in gills. Symbiosis with chemoautotrophic bacteria has, so far, not been proved for Vesicomya and the genus is not restricted to sulphide-rich reducing habitats. The subfamily Pliocardiinae currently contains about 15 genera with mostly medium or large body size, characterized by the presence of subfilamental tissue in the gills. The Pliocardiinae are highly specialized for sulphide-rich reducing environments, harbouring chemoautrophic bacteria in their gills. This is the first summary of the generic structure of the family Vesicomyidae that allow us to analyze the distribution of vesicomyids at the generic level. We recognize here five different distribution patterns that are related to the specific environmental demands. The general trends in the distribution patterns of the vesicomyids are an occurrence of the majority of genera in broad geographical ranges and the prevalence of near continental type of distribution. PMID:20376362

  6. Indirect Evidence on Sex Reversal of Sinonovacula constricta (Bivalvia: Euheterodonta) and Gomphina veneriformis (Bivalvia: Veneridae)

    PubMed Central

    Shin, Yun Kyung; Park, Jung Jun; Choi, Ji Sung; Lee, Jung Sick

    2014-01-01

    This study attempts to propose the possibility of the sex reversal in Sinonovacula constricta and Gomphina veneriformis by confirming the changes in the sex ratio with the shell length in the same population level. For analysis of sex ratio, 100 individuals of S. constricta (SL 26.5-95.0 mm) and 2385 individuals of G. veneriformis (SL 15.1-60.1 mm) were used. Sex was analyzed histologically. Both species displayed the tendency of increase in the female proportion with increase in shell length. In this study, changes in the sex ratio in accordance with the growth of S. constricta and G. veneriformis are determined to be indirect evidence that signifies their sex reversal. PMID:25949174

  7. Metal bioaccumulation in consumed marine bivalves in Southeast Brazilian coast.

    PubMed

    Lino, A S; Galvão, P M A; Longo, R T L; Azevedo-Silva, C E; Dorneles, P R; Torres, J P M; Malm, O

    2016-03-01

    This work aimed to investigate metal bioaccumulation by mussels (Perna perna) and Lion's Scallop (Nodipecten nodosus) farmed in tropical bays, in order to estimate spatial and temporal variation in the exposure to these elements, as well as human health risk. The concentration of each measured element was considered for this evaluation, using maximum residue level (MRL) in foods established by the Brazilian (ANVISA), American (USFDA) and European Communities (EC) legislations. Values for estimated daily ingestion (EDI) were determined for metals intake through mussel and scallop consumption. These estimates were compared with the reference value of (PTDI) proposed by World Health Organization (WHO). Trace elements concentration was measured on ninety mussels P. perna (tissue) and ninety Lion's Scallop N. nodosus (muscle and gonad) reared in four different tropical areas of the Southeast Brazilian coast, between 2009 and 2010. Zinc (Zn), Iron (Fe), Copper (Cu), Manganese (Mn), Chrome (Cr), Nickel (Ni), Cadmium (Cd) and Lead (Pb) concentrations were measured by flame atomic absorption spectrometry after acid mineralization. Cd and Mn were more efficiently bioaccumulated by scallops than mussels and the opposite was found for Fe, Cu and Ni. Guanabara Bay and Sepetiba Bay were considered the most impacted between ecosystems studied. Higher Cd values in Arraial do Cabo in the other sites studied were associated with upwelling that occurs in the region. Consumption of both species cannot be considered safe, because the Cu and Cr concentrations, in accordance with the limits established by the Brazilian Agency (ANVISA). On the other hand, any EDI value exceeded the corresponding value of the PTDI, proposed by World Health Organization (WHO). PMID:26854245

  8. Global existence in L sup 1 for the modified nonlinear Enskog equation in R sup 3

    SciTech Connect

    Polewczak, J. )

    1989-07-01

    A global existence theorem with large initial data in L{sup 1} is given for the modified Enskog equation in R{sup 3}. The method, which is based on the existence of a Liapunov functional (analog of the H-Boltzmann theorem), utilizes a weak compactness argument in L{sup 1} in a similar way to the DiPerna-Lions proof for the Boltzmann equation. The existence theorem is obtained under certain condition on the behavior of the geometric factor Y. The condition on Y amounts to the fact that the L{sup 1} norm of the collision term grows linearly when the local density tends to infinity.

  9. On a Kinetic Equation for Coalescing Particles

    NASA Astrophysics Data System (ADS)

    Escobedo, Miguel; Laurençot, Philippe; Mischler, Stéphane

    Existence of global weak solutions to a spatially inhomogeneous kinetic model for coalescing particles is proved, each particle being identified by its mass, momentum and position. The large time convergence to zero is also shown. The cornestone of our analysis is that, for any nonnegative and convex function, the associated Orlicz norm is a Liapunov functional. Existence and asymptotic behaviour then rely on weak and strong compactness methods in L1 in the spirit of the DiPerna-Lions theory for the Boltzmann equation.

  10. Global existence in L 1 for the modified nonlinear Enskog equation in ℝ3

    NASA Astrophysics Data System (ADS)

    Polewczak, Jacek

    1989-07-01

    A global existence theorem with large initial data in L 1 is given for the modified Enskog equation in ℝ3. The method, which is based on the existence of a Liapunov functional (analog of the H-Boltzmann theorem), utilizes a weak compactness argument in L 1 in a similar way to the DiPerna-Lions proof for the Boltzmann equation. The existence theorem is obtained under certain condition on the behavior of the geometric factor Y. The condition on Y amounts to the fact that the L 1 norm of the collision term grows linearly when the local density tends to infinity.

  11. Polonium-210 in marine mussels (bivalve molluscs) inhabiting the southern coast of India.

    PubMed

    Khan, M Feroz; Wesley, S Godwin; Rajan, M P

    2014-12-01

    The present study focused on the determination of the alpha-emitter, (210)Po, in two species of marine mussels (bivalve molluscs) commonly available in the southern coastal region of India. The brown mussel, Perna indica was collected from the west coast and the green mussel, Perna viridis from the east coast. The concentration of (210)Po was related to the allometry (length of shell, wet/dry weight of shell/soft tissue) of the mussels and significant results were found. The study period focused on three seasons namely, pre-monsoon, monsoon and post-monsoon for a 1-year period (2010-2011). The results revealed higher activity levels in smaller-sized mussels compared to larger ones. Marked variation in (210)Po activity concentration was noted in the whole-body soft tissues between seasons and sampling site (p < 0.05). The dose rate assessment for mussels was performed using the ERICA Assessment tool. The chronic exposure to mussels due to (210)Po was found to be lesser than the global benchmark dose rate of 10 μGy h(-1). The effective ingestion dose to adults who intake mussels was estimated to be in the range 5.1-34.9 μSv y(-1). The measurement contributes to the furthering of knowledge of (210)Po, since no data exist in this region. PMID:25042075

  12. Mussels as ecosystem engineers: Their contribution to species richness in a rocky littoral community

    NASA Astrophysics Data System (ADS)

    Borthagaray, Ana Inés; Carranza, Alvar

    Mussels are important ecosystem engineers in marine benthic systems because they aggregate into beds, thus modifying the nature and complexity of the substrate. In this study, we evaluated the contribution of mussels ( Brachidontes rodriguezii, Mytilus edulis platensis, and Perna perna) to the benthic species richness of intertidal and shallow subtidal communities at Cerro Verde (Uruguay). We compared the richness of macro-benthic species between mussel-engineered patches and patches without mussels but dominated by algae or barnacles at a landscape scale (all samples), between tidal levels, and between sites distributed along a wave exposition gradient. Overall, we found a net increase in species richness in samples with mussels (35 species), in contrast to samples where mussels were naturally absent or scarce (27 species). The positive trend of the effect did not depend upon tidal level or wave exposition, but its magnitude varied between sites. Within sites, a significant positive effect was detected only at the protected site. Within the mussel-engineered patches, the richness of all macro-faunal groups (total, sessile and mobile) was positively correlated with mussel abundance. This evidence indicates that the mussel beds studied here were important in maintaining species richness at the landscape-level, and highlights that beds of shelled bivalves should not be neglected as conservation targets in marine benthic environments.

  13. Ecological relevance of Sentinels' biomarker responses: a multi-level approach.

    PubMed

    Seabra Pereira, Camilo D; Abessa, Denis M S; Choueri, Rodrigo B; Almagro-Pastor, Victor; Cesar, Augusto; Maranho, Luciane A; Martín-Díaz, María Laura; Torres, Ronaldo J; Gusso-Choueri, Paloma K; Almeida, João E; Cortez, Fernando S; Mozeto, Antonio A; Silbiger, Helcy L N; Sousa, Eduinetty C P M; Del Valls, Tommas Angel; Bainy, Afonso C D

    2014-05-01

    In response to the need for more sensitive and rapid indicators of environmental quality, sublethal effects on the lowest levels of biological organization have been investigated. The ecological relevance of these responses assumes a prevailing role to assure effectiveness as indicator of ecological status. This study aimed to investigate the linkages between biomarker responses of caged bivalves and descriptive parameters of macrobenthic community structure. For this purpose a multi-level environmental assessment of marine and estuarine zones was performed in São Paulo coast, Brazil. Multivariate analysis was applied to identify linkages between biological responses and ecological indices, as well as to characterizing the studied stations. Individuals of the marine mussel Perna perna caged along Santos Bay showed signs of oxidative stress, lysosomal membrane destabilization, histological alterations and reduced embryonic development. The estuarine oyster Crassostrea rhizophorae caged along Santos Port Channel showed alterations on biotransformation enzymes and antioxidant system, DNA damage and lysosomal membrane destabilization. The benthic community analysis showed reduced richness and diversity in the same areas of the Santos bay and estuary where biomarker responses were altered. Our results revealed that xenobiotics are inducing physiological stress, which may lead to changes of the benthic community structure and deterioration of the ecological status over time. Integrating biomarker responses and ecological indexes improved certainty that alterations found at community level could be related to xenobiotic as stressors, which was very useful to improve the discriminatory power of the environmental assessment. PMID:24314371

  14. Antifouling activity of twelve demosponges from Brazil.

    PubMed

    Ribeiro, S M; Rogers, R; Rubem, A C; Da Gama, B A P; Muricy, G; Pereira, R C

    2013-08-01

    Benthic marine organisms are constantly exposed to fouling, which is harmful to most host species. Thus, the production of secondary metabolites containing antifouling properties is an important ecological advantage for sessile organisms and may also provide leading compounds for the development of antifouling paints. High antifouling potential of sponges has been demonstrated in the Indian and Pacific oceans and in the Caribbean and Mediterranean seas. Brazilian sponges remain understudied concerning antifouling activities. Only two scientific articles reported this activity in sponges of Brazil. The objective of this study was to test crude extracts of twelve species of sponges from Brazil against the attachment of the mussel Perna perna through laboratorial assays, and highlight promising species for future studies. The species Petromica citrina, Amphimedon viridis, Desmapsamma anchorata, Chondrosia sp., Polymastia janeirensis, Tedania ignis, Aplysina fulva, Mycale angulosa, Hymeniacidon heliophila, Dysidea etheria, Tethya rubra, and Tethya maza were frozen and freeze-dried before extraction with acetone or dichloromethane. The crude extract of four species significantly inhibited the attachment of byssus: Tethya rubra (p = 0.0009), Tethya maza (p = 0.0039), Petromica citrina (p = 0.0277), and Hymeniacidon heliophila (p = 0.00003). These species, specially, should be the target of future studies to detail the substances involved in the ability antifouling well as to define its amplitude of action. PMID:24212689

  15. Effects of different biotic substrata on mussel attachment.

    PubMed

    Ank, Glaucia; Porto, Tiago F; Pereira, Renato C; da Gama, Bernardo A P

    2009-01-01

    Surface colonization by invertebrates can be stimulated or inhibited by cues produced by biofilms, conspecifics or other macroorganisms. To study the effects of living substrata on the attachment of the brown mussel, Perna perna, two different approaches were employed: (1) mussels were distributed in sets of Petri dishes consisting of one sterile set (controls), three sets in which marine biofilms were allowed to develop in aquaria for 1, 7 or 15 days and another set that had been immersed in a natural marine environment for 1-day. There was no significant effect of biofilms on attachment, suggesting that neither age nor the source of the biofilm influenced attachment. (2) Mussels were suspended over PVC panels (controls) and over panels on which Balanus trigonus (Crustacea), Schizoporella errata (Bryozoa), Symplegma rubra or Didemnum speciosum (Ascidiacea) were present. Attachment was significantly higher on the controls and on B. trigonus than on colonial taxa such as S. rubra, S. errata and D. speciosum, probably due to antifouling defenses of these species. The results show that the composition of the biological substratum is an important factor affecting mussel behavior. PMID:19048423

  16. Experimental studies of succession and stability in rocky intertidal communities subject to artisanal shellfish gathering

    NASA Astrophysics Data System (ADS)

    Dye, A. H.

    Rocky-shore communities on the east coast of southern Africa are subject to intense shellfish exploitation by coastal people. Large-scale removal of sessile species, such as the mussel Perna perna, creates areas of bare rock, providing space for colonization. Rates of recolonization of experimentally-cleared areas in both protected and exploited sites were found to be variable. There was as much as a two-year delay before sessile macro-organisms reappeared, and the course of subsequent succession depended on the nature of the initial colonists. Large spatial and temporal variations in species diversity and richness were observed where it appeared that emergent communities were less stable than adjacent controls. After eight to nine years, few of the cleared areas have developed communities similar to the original or to controls. These results are compared with those of a controlled exploitation experiment conducted in a nature reserve. Similar results were obtained despite the fact that exploitation was more selective for target species and did not involve total clearance. The long-term effects of human exploitation involve shifts in community structure towards earlier successional stages which may persist for long periods of time. Consequently, management options such as rotational cropping may be inappropriate in such a system.

  17. Paralytic shellfish poisoning (PSP) in Margarita Island, Venezuela.

    PubMed

    La Barbera-Sánchez, Amelia; Franco Soler, Jose; Rojas de Astudillo, Luisa; Chang-Yen, Ivan

    2004-09-01

    A severe outbreak of Paralytic Shellfish Poisoning (PSP) occurred in Manzanillo and Guayacán, northwestern coast of Margarita Island, Venezuela, between August and October 1991. A bloom of dinoflagellates including Prorocentrum gracile, Gymnodinium catenatum and Alexandrium tamarense seemed to be responsible for this outbreak. Levels of PSP toxins in mussels (Perna perna) exceeded the international safety limit of saxitoxin, 80 microg STX/100 microg meat. PSP toxin values varied between 2548 and 115 microg STX/100 g meat in Manzanillo, and between 1422 and 86 microg STX/100 g meat in Guayacán. At both locations, the highest levels were detected in August, when 24 patients exhibited typical symptoms of PSP toxicity after consuming cooked mussels (16 required hospitalization). A high pressure liquid chromatographic (HPLC) procedure was recently used on the 1991 samples. The major toxin detected in samples of both locations was decarbamoyl saxitoxin (dcSTX), but low concentrations of saxitoxin were also found in Manzanillo samples. Gonyautoxins GTX1, GTX2 and GTX3 were detected only at Guayacán, while in both locations, decarbamoylgonyatouxin (dcGTX2,3) toxins were detected. These findings represent the first time that causative toxins of PSP in Venezuela have been chemically identified, and confirm the presence of dcSTX and dcGTX in mussels from the Caribbean Sea. The presence of dcSTX and dcGTX in shellfish is indicative that Gymnodinium catenatum was a causative organism for outbreak of PSP. PMID:17465121

  18. Intraspecific variability and systematics in South American Syrotrigoniinae (Trigoniida, Bivalvia)

    NASA Astrophysics Data System (ADS)

    Echevarría, Javier; Damborenea, Susana E.; Manceñido, Miguel O.

    2015-04-01

    The systematics of the genus Syrotrigonia is revised in the light of the intraspecific variability of a large sample of Syrotrigonia sigeli from the Valanginian from Neuquén Basin, Argentina. The genus can be recognized by the presence of concentric or subconcentric costae surrounding the umbo, later on developing an inflection and finally resulting in a set of anterior horizontal to commarginal costae and another set of posterior sub-vertical costae. The anterior part of the area bears transverse, usually anteriorly concave, costae which direct towards the umbo on the escutcheon; initially they are continuous with those on the flank, but later on they usually alternate. General shell shape, the presence of an antecarinal sulcus, the junction pattern between both sets of costae and the number of horizontal costae relative to vertical costae are variable among species, while costae width or density and the development of horizontal vs. commarginal costae may vary highly within species. The presence of commarginal rugae developed on the whole surface of the shell is interpreted as a result of environmental perturbations. A brief biogeographical interpretation of the family Buchotrigoniidae is also outlined. Syrotrigonia probably originated in North America in the Tithonian, being widespread in the Pacific coast of South America by Early Cretaceous times; at least six (probably seven) South American species could be recognized. By Aptian times the taxon reached the Tethyan realm, its last record being Aptian or Albian in age. The frequent presence of different species in marginal marine deposits suggests a euryhaline lineage adapted to salinity variations, this may also be the cause of the frequent presence of commarginal rugae. Considering the high variability displayed in the analyzed material, large samples are needed to characterize new species within the group.

  19. Sublethal foot-predation on Donacidae (Mollusca: Bivalvia)

    NASA Astrophysics Data System (ADS)

    Salas, Carmen; Tirado, Cristina; Manjón-Cabeza, Maria Eugenia

    2001-08-01

    The incidence of foot nipping was studied on the Donax spp. of the littoral of Málaga (Southern Spain, 2875 specimens collected from February 1990 to January 1991) and of Ré island (French Atlantic coast, 262 specimens of Donax vittatus (Da Costa, 1778) collected in May 1996). In Málaga, Donax trunculus L., 1758 was the species most regularly nipped (18% of individuals), with peaks in summer (25% in August and 48% in September) and winter (34% in December). In Ré island, 27% of the specimens showed a nipped foot. Logistic regression shows that in D. trunculus length is the variable that most influences the probability of foot nipping, followed by weight and chlorophyll a. However, the difference in length between damaged and undamaged individuals was not significant (U-Mann-Whitney test). The size class frequency and the values of Ivlev's index show that the small size classes were avoided, while for the other size classes predation remained balanced throughout the year. Therefore, the avoidance of the small size classes makes length the most influential variable. The logistic regression indicated a coefficient B=-0.03 for weight. This implies a slightly negative influence on the probability of foot nipping. However, without the data of September, there is a positive correlation ( r=0.76, p<0.01) between the monthly percentages of predation and the flesh dry weight of a standard individual (25 mm long). The peak in September could be due to the recruitment peak of bivalves, which may have attracted more predators to the area, and/or to the recruitment of predators such as crabs to the swash zone. Logistic regression and test of comparison of percentages indicate that there was not any influence of the sex of an animal on the probability of foot nipping. Only in February was a significantly higher percentage ( p<0.05) of females nipped (44.44%) than the total of females in the sample (20.20%). The biomass (as flesh dry weight) of D. trunculus lost by foot nipping amounts to more than 20% in most of the size classes. There was an increase from the small sizes to the largest ones, in which it reaches 37%, with a positive correlation ( r=0.84; p<0.005) between size class and loss of biomass. Possible predators responsible for the foot nipping are crabs. Crab species usually found together with the donacids were Portumnus latipes (Pennant, 1777) Liocarcinus vernalis (Risso, 1816) and Atelecyclus undecimdentatus (Herbst, 1783). In aquarium experiments, they demonstrated an ability to nip the foot of clams. Portumnus latipes was the most active foot nipper, but left alive all the damaged clams. Therefore, we conclude that crabs are the most likely foot-nipping predators in the field.

  20. The behaviour of giant clams (Bivalvia: Cardiidae: Tridacninae).

    PubMed

    Soo, Pamela; Todd, Peter A

    2014-01-01

    Giant clams, the largest living bivalves, live in close association with coral reefs throughout the Indo-Pacific. These iconic invertebrates perform numerous important ecological roles as well as serve as flagship species-drawing attention to the ongoing destruction of coral reefs and their associated biodiversity. To date, no review of giant clams has focussed on their behaviour, yet this component of their autecology is critical to their life history and hence conservation. Almost 100 articles published between 1865 and 2014 include behavioural observations, and these have been collated and synthesised into five sections: spawning, locomotion, feeding, anti-predation, and stress responses. Even though the exact cues for spawning in the wild have yet to be elucidated, giant clams appear to display diel and lunar periodicities in reproduction, and for some species, peak breeding seasons have been established. Perhaps surprisingly, giant clams have considerable mobility, ranging from swimming and gliding as larvae to crawling in juveniles and adults. Chemotaxis and geotaxis have been established, but giant clams are not phototactic. At least one species exhibits clumping behaviour, which may enhance physical stabilisation, facilitate reproduction, or provide protection from predators. Giant clams undergo several shifts in their mode of acquiring nutrition; starting with a lecithotrophic and planktotrophic diet as larvae, switching to pedal feeding after metamorphosis followed by the transition to a dual mode of filter feeding and phototrophy once symbiosis with zooxanthellae (Symbiodinium spp.) is established. Because of their shell weight and/or byssal attachment, adult giant clams are unable to escape rapidly from threats using locomotion. Instead, they exhibit a suite of visually mediated anti-predation behaviours that include sudden contraction of the mantle, valve adduction, and squirting of water. Knowledge on the behaviour of giant clams will benefit conservation and restocking efforts and help fine-tune mariculture techniques. Understanding the repertoire of giant clam behaviours will also facilitate the prediction of threshold levels for sustainable exploitation as well as recovery rates of depleted clam populations. PMID:25414524

  1. Complete mitochondrial genome of Ostrea denselamellosa (Bivalvia, Ostreidae).

    PubMed

    Yu, Hong; Kong, Lingfeng; Li, Qi

    2016-01-01

    The complete mitochondrial (mt) genome of the flat oyster, Ostrea denselamellosa, was determined using Long-PCR and genome walking techniques in this study. The total length of the mt genome sequence of O. denselamellosa was 16,227 bp, which is the smallest reported Ostreidae mt genome to date. It contained 12 protein-coding genes (lacking of ATP8), 23 transfer RNA genes, and two ribosomal RNA genes. A bias towards a higher representation of nucleotides A and T (60.7%) was detected in the mt genome of O. denselamellosa. The rrnL was split into two fragments (3' half, 711 bp; 5' half, 509 bp), which seems to be the unique characteristics of Ostreidae mt genomes. PMID:24779597

  2. Methanotrophic marine molluscan (Bivalvia, Mytilidae) symbiosis: mussels fueled by gas

    SciTech Connect

    Childress, J.J.; Fisher, C.R.; Brooks, J.M.; Kennicutt, M.C. II; Bidigare, R.; Anderson, A.E.

    1986-09-19

    An undescribed mussel (family Mytilidae), which lives in the vicinity of hydrocarbon seeps in the Gulf of Mexico, consumes methane (the principal component of natural gas) at a high rate. The methane consumption is limited to the gills of these animals and is apparently due to the abundant intracellular bacteria found there. This demonstrates a methane-based symbiosis between an animal and intracellular bacteria. Methane consumption is dependent on the availability of oxygen and is inhibited by acetylene. The consumption of methane by these mussels is associated with a dramatic increase in oxygen consumption and carbon dioxide production. As the methane consumption of the bivalve can exceed its carbide dioxide production, the symbiosis may be able to entirely satisfy its carbon needs from methane uptake. The very light (delta/sup 13/C = -51 to -57 per mil) stable carbon isotope ratios found in this animal support methane (delta/sup 13/C = -45 per mil at this site) as the primary carbon source for both the mussels and their symbionts. 19 references, 2 figures, 1 table.

  3. Carbonate-associated sulfate in lucinid (Bivalvia) shells

    NASA Astrophysics Data System (ADS)

    Peng, Y.; Bao, H.; Anderson, L.; Engel, A. S.

    2007-12-01

    Symbiosis is a fundamental driver of evolution, with examples ranging from mitochondria in eukaryotic cells to barnacle-whale commensalism. The association between sulfur-oxidizing (thiotrophic) bacteria and the lucinid bivalve clade is particularly intriguing because the inferred antiquity of the relationship (>400 m.y.) seems at odds with the relatively loose ecologic linkage of living members. Because only half of genus-level lucinid taxa are extant, and the δ13C of shell carbonate exhibits no systematic difference between symbiotic and non- symbiotic bivalves, a new morphologically-independent proxy to determine whether fossil taxa possessed thiotrophic endosymbionts is needed. The δ34S of carbonate-associated sulfate (CAS) in bivalve shells may hold promise because biogenic carbonate incorporates sulfate into its crystal structure during biomineralization. Incorporation of bacterially derived SO42- (with a more negative δ34S value due to its reduced sulfur origin) into the lucinid-shell crystal lattice would, therefore, impart a distinctly lower δ34SCAS value than that from seawater SO42-, and would be distinguishable from CAS values of co- occurring heterotrophic bivalves. We measured CAS contents, δ34SCAS and δ18OCAS values of 15 sets of lucinid and co-occurring infaunal and epifaunal heterotrophic bivalve shells collected from modern and Cenozoic shallow marine sites. The modern bivalve shells had variable CAS content, from 100 to 2600 ppm. Epifauna often had the highest concentrations relative to the other ecological groups. The δ34SCAS and δ18OCAS clustered at values corresponding to modern seawater sulfate, but with significant scatter. There was no systematic isotope- compositional difference among all bivalves in the same habitat, or among the same lucinid, infaunal, or epifaunal groups across different sites. The fossil bivalve shells tended to preserve lower CAS concentrations and the isotope compositions further deviated from seawater values. These data suggest that 1) pore-water sulfate in shallow sediments is highly heterogeneous in its concentration and isotope composition, probably due to active microbial sulfate reduction, bioturbation, and water-pumping by bivalves and other infaunal filter feeders; 2) CAS is derived from ambient porewater or pumped-in seawater for infauna or epifauna, as well as for lucinids; and 3) CAS concentration and isotope compositions are vulnerable to later diagenetic processes.

  4. The complete mitochondrial genome of Crassostrea gasar (Bivalvia: Ostreidae).

    PubMed

    Cavaleiro, Nathalia P; Solé-Cava, Antonio M; Melo, Cláudio M R; de Almeida, Luiz G; Lazoski, Cristiano; Vasconcelos, Ana Tereza R

    2016-07-01

    The complete mitochondrial genome of Crassostrea gasar was sequenced using the Ion Proton technology in combination with 454 Roche GS-FLX plataform data. We assembled a 17,686 bp complete circular mitochondrial genome, containing 13 protein-coding genes, a major non-coding region (MNR), two ribosomal RNA genes and 24 transfer RNA genes. Phylogenetic analysis of concatenated amino acid sequences from mitochondria showed monophyletic clades formed with high bootstrap values. This is the first complete mitochondrial sequence of an oyster from South America. Mitogenome sequence was deposited in GenBank under the accession number KR856227. PMID:27158791

  5. Evidence for PSP in mussels in Trinidad.

    PubMed

    Ammons, D; Rampersad, J; Poli, M A

    2001-06-01

    Herein we present the first evidence for the presence of Paralytic Shellfish Poison (PSP) in Trinidadian waters. The toxin was found in a meat extract of the mussel, Perna viridis. PSP has not previously been demonstrated in the shellfish of Caribbean islands. The presence of PSP in Trinidad is therefore significant in that it presents an opportunity to better understand the dynamics of PSP and algal blooms in both a region and island environment not normally associated with PSP.P. viridis is not native to Trinidad, but rather originates from eastern Asia. It presented itself only recently in Trinidadian waters. Interestingly, shellfish consumption and algal blooms have had a long history of coexistence in Trinidad without any record of human intoxications. In this context, potential Public Health implications of finding PSP in a non-native shellfish species are briefly discussed. PMID:11137550

  6. Heavy metals in bivalve mollusks collected from Da-Peng Bay Lagoon in south-southwestern Taiwan.

    PubMed

    Shue, Meei-Fang; Chen, Wen-Der; Su, Chia-Chi; Lu, Ming-Chun

    2014-01-01

    In this study, concentrations of several heavy metals (Cu, Pb, Zn, Ni, Cr, and Cd) were measured in Katelysia hiantina, Anomalocardia squamosa, Perna viridis, Anadara antiquata, Paphia undulata, and Sanguinolaria diphos bivalve mollusks from Da-Peng Bay Lagoon near the south-southwestern coast of Taiwan. The metal pollution index (MPI) values were highest and lowest in winter and autumn, respectively. The MPI value in the viscera of P. viridis was higher than in muscles. In all four seasons, Zn concentrations in viscera and muscles of P. viridis were higher than for other metals. The capacities of A. squamosa to accumulate the concentrations of Cu, Ni, and Cr and of A. antiquata to accumulate concentrations of Pb, Zn, and Cd were significant. Analytical results suggested that A. squamosa and A. antiquata may be used as bioindicators for monitoring Cu, Ni, Cr, Pb, Zn, and Cd heavy-metal pollution in Da-Peng Bay Lagoon throughout the year. PMID:24555680

  7. Uniqueness and Long Time Asymptotic for the Keller-Segel Equation: The Parabolic-Elliptic Case

    NASA Astrophysics Data System (ADS)

    Egaña Fernández, Giani; Mischler, Stéphane

    2016-06-01

    The present paper deals with the parabolic-elliptic Keller-Segel equation in the plane in the general framework of weak (or "free energy") solutions associated to initial datum with finite mass M, finite second moment and finite entropy. The aim of the paper is threefold: (1) We prove the uniqueness of the "free energy" solution on the maximal interval of existence [0, T*) with T* = ∞ in the case when M ≦ 8π and T* < ∞ in the case when M > 8π. The proof uses a DiPerna-Lions renormalizing argument which makes it possible to get the "optimal regularity" as well as an estimate of the difference of two possible solutions in the critical L 4/3 Lebesgue norm similarly to the 2 d vorticity Navier-Stokes equation.

  8. Confirmatory factor analysis of the Early Arithmetic, Reading, and Learning Indicators (EARLI)☆

    PubMed Central

    Norwalk, Kate E.; DiPerna, James Clyde; Lei, Pui-Wa

    2015-01-01

    Despite growing interest in early intervention, there are few measures available to monitor the progress of early academic skills in preschoolers. The Early Arithmetic, Reading, and Learning Indicators (EARLI; DiPerna, Morgan, & Lei, 2007) were developed as brief assessments of critical early literacy and numeracy skills. The purpose of the current study was to examine the factor structure of the EARLI probes via confirmatory factor analysis (CFA) in a sample of Head Start preschoolers (N = 289). A two-factor model with correlated error terms and a bifactor model provided comparable fit to the data, although there were some structural problems with the latter model. The utility of the bifactor model for explaining the structure of early academic skills as well as the utility of the EARLI probes as measures of literacy and numeracy skills in preschool are discussed. PMID:24495496

  9. Trace metals in water, sediment and bivalves of a tropical estuary, west coast of India.

    PubMed

    Parvez Al-Usmani, S M; Jagtap, T G; Patil, D N

    2015-10-15

    Trace metal pollution was studied in water, sediment and three selected bivalves in Mandovi and Chapora estuaries of Goa. The trace metal in water and sediment of Mandovi was higher than in Chapora. The concentration in the tissues was in the range of 1205.2-2506.7 ppm for Paphia malabarica, 1906.2-2802.6 ppm for Perna viridis and 778.7-1607.5 ppm for Saccostrea cucullata in Mandovi estuary. Tha values for Chapora were 199.4-625.8 ppm for P. malabarica, 812.6-1220.2 for P. viridis and 392.5-418.6 ppm for S. cucullata. The anthropogenic input of metal in Mandovi estuary appears to be mainly responsible for the high accumulation of trace metals. These bivalves have potential to serve as indicator for metal contamination in seafood of Goa. PMID:26228069

  10. Confirmatory factor analysis of the Early Arithmetic, Reading, and Learning Indicators (EARLI).

    PubMed

    Norwalk, Kate E; DiPerna, James Clyde; Lei, Pui-Wa

    2014-02-01

    Despite growing interest in early intervention, there are few measures available to monitor the progress of early academic skills in preschoolers. The Early Arithmetic, Reading, and Learning Indicators (EARLI; DiPerna, Morgan, & Lei, 2007) were developed as brief assessments of critical early literacy and numeracy skills. The purpose of the current study was to examine the factor structure of the EARLI probes via confirmatory factor analysis (CFA) in a sample of Head Start preschoolers (N=289). A two-factor model with correlated error terms and a bifactor model provided comparable fit to the data, although there were some structural problems with the latter model. The utility of the bifactor model for explaining the structure of early academic skills as well as the utility of the EARLI probes as measures of literacy and numeracy skills in preschool are discussed. PMID:24495496

  11. Accumulation patterns of lipophilic organic contaminants in surface sediments and in economic important mussel and fish species from Jakarta Bay, Indonesia.

    PubMed

    Dwiyitno; Dsikowitzky, Larissa; Nordhaus, Inga; Andarwulan, Nuri; Irianto, Hari Eko; Lioe, Hanifah Nuryani; Ariyani, Farida; Kleinertz, Sonja; Schwarzbauer, Jan

    2016-09-30

    Non-target screening analyses were conducted in order to identify a wide range of organic contaminants in sediment and animal tissue samples from Jakarta Bay. High concentrations of di-iso-propylnaphthalenes (DIPNs), linear alkylbenzenes (LABs) and polycyclic aromatic hydrocarbons (PAHs) were detected in all samples, whereas phenylmethoxynaphthalene (PMN), DDT and DDT metabolites (DDX) were detected at lower concentrations. In order to evaluate the uptake and accumulation by economic important mussel (Perna viridis) and fish species, contaminant patterns of DIPNs, LABs and PAHs in different compartments were compared. Different patterns of these contaminant groups were found in sediment and animal tissue samples, suggesting compound-specific accumulation and metabolism processes. Significantly higher concentrations of these three contaminant groups in mussel tissue as compared to fish tissue from Jakarta Bay were found. Because P. viridis is an important aquaculture species in Asia, this result is relevant for food safety. PMID:26853592

  12. Detection of a parasitic amoeba (Order Dactylopodida) in the female gonads of oysters in Brazil.

    PubMed

    Sühnel, Simone; Ivachuk, Celene da S; Schaefer, Ana L C; Pontinha, Vitor A; Martins, Maurício L; Figueras, Antonio; Meyer, Gary R; Jones, Simon R M; Stewart, Johnson C; Gurney-Smith, Helen J; Magalhães, Aimê R M; Bower, Susan M

    2014-07-01

    The impacts of oocyte parasites on the reproductive success of molluscs are largely unknown. In this study, we evaluated the presence of gonad parasites in 6 species of marine bivalve molluscs native to southern Brazil. Cultured bivalves included the mangrove oyster Crassostrea gasar (sometimes called C. brasiliana), the brown mussel Perna perna, the lion's paw scallop Nodipecten nodosus and the wing pearl oyster Pteria hirundo. Another species of mangrove oyster, C. rhizophorae, and the carib pointed venus clam Anomalocardia brasiliana (syn. A. flexuosa) were collected from the wild. Molluscs were collected in winter 2009 and summer 2010 for histopathological and molecular evaluation. An unknown ovarian parasite (UOP) was observed in histopathological sections of female gonads of C. gasar and C. rhizophorae. The UOP possessed features suggestive of amoebae, including an irregular outer membrane, frothy cytoplasm, a nucleus with a prominent central nucleolus and a closely associated basophilic parasome. PCR analysis was negative for Marteilioides chungmuensis, Perkinsus spp. and Paramoeba perurans. However, real-time PCR successfully amplified DNA from oyster gonads when using universal Paramoeba spp. primers. Also, conventional PCR amplified DNA using primers specific for Perkinsela amoebae-like organisms (syn. Perkinsiella), which are considered as endosymbionts of Parameoba spp., previously thought to be the parasome. Our results suggest that this UOP is a species of amoeba belonging to 1 of the 2 families of the order Dactylopodida, possibly related to Paramoeba spp. This study represents the first report of this type of organism in oysters. We found that C. gasar and C. rhizophorae were the most susceptible molluscs to these UOPs. PMID:24991850

  13. Comparison of metal accumulation in mussels at different local and global scales.

    PubMed

    Blackmore, Graham; Wang, Wen-Xiong

    2003-02-01

    Cadmium and zinc uptake from the dissolved phase, assimilation efficiency (AE) from the dietary phase, and body burden as well as clearance rate were measured in green mussels, Perna viridis, and blue mussels Mytilus edulis, M. galloprovincialis and Mytilus trossulus. Perna viridis was collected from four sites differentially enriched with trace metals in Hong Kong and blue mussels were collected from different climatic zones, i.e., subarctic and temperate, to allow comparisons with the more tropical green mussels. Despite similar shell length, the dry weight of mussels varied significantly between sites and species and this had a large effect on Cd and Zn accumulation, clearance rate, and metal body burden. All data were, therefore, weight adjusted to allow comparison without this confounding factor. Trace-metal body concentrations were significantly different between sites, and P. viridis collected from Tsing Yi, Hong Kong, had the highest levels of all measured metals when compared with other Hong Kong sites. There was, however, no relationship between the degree of metal enrichment and the Cd and Zn uptake (both from dissolved and particulate sources) and clearance rates. Furthermore, Cd and Zn uptake (dissolved and particulate) and clearance rate varied little between species or climatic zones of collection. Thus, over the range of body trace-metal concentrations measured and between mussel species over large geographical distances and climatic zones, the uptake rates, AEs, and clearance rates are similar when measured under the same laboratory conditions after body-size correction. When other factors such as salinity are also corrected, biomonitoring data from different areas and even utilizing different mussel species may be directly comparable. This study therefore provides important evidence in support of Mussel Watch Programs. PMID:12558172

  14. Effects of Endolithic Parasitism on Invasive and Indigenous Mussels in a Variable Physical Environment

    PubMed Central

    McQuaid, Christopher David; Gektidis, Marcos

    2009-01-01

    Biotic stress may operate in concert with physical environmental conditions to limit or facilitate invasion processes while altering competitive interactions between invaders and native species. Here, we examine how endolithic parasitism of an invasive and an indigenous mussel species acts in synergy with abiotic conditions of the habitat. Our results show that the invasive Mytilus galloprovincialis is more infested than the native Perna perna and this difference is probably due to the greater thickness of the protective outer-layer of the shell of the indigenous species. Higher abrasion due to waves on the open coast could account for dissimilarities in degree of infestation between bays and the more wave-exposed open coast. Also micro-scale variations of light affected the level of endolithic parasitism, which was more intense at non-shaded sites. The higher levels of endolithic parasitism in Mytilus mirrored greater mortality rates attributed to parasitism in this species. Condition index, attachment strength and shell strength of both species were negatively affected by the parasites suggesting an energy trade-off between the need to repair the damaged shell and the other physiological parameters. We suggest that, because it has a lower attachment strength and a thinner shell, the invasiveness of M. galloprovincialis will be limited at sun and wave exposed locations where endolithic activity, shell scouring and risk of dislodgement are high. These results underline the crucial role of physical environment in regulating biotic stress, and how these physical-biological interactions may explain site-to-site variability of competitive balances between invasive and indigenous species. PMID:19668334

  15. Patchiness and Co-Existence of Indigenous and Invasive Mussels at Small Spatial Scales: The Interaction of Facilitation and Competition

    PubMed Central

    Erlandsson, Johan; McQuaid, Christopher D.; Sköld, Martin

    2011-01-01

    Ecological theory predicts that two species with similar requirements will fail to show long-term co-existence in situations where shared resources are limiting, especially at spatial scales that are small relative to the size of the organisms. Two species of intertidal mussels, the indigenous Perna perna and the invasive Mytilus galloprovincialis, form mixed beds on the south coast of South Africa in a situation that has been stable for several generations of these species, even though these populations are often limited by the availability of space. We examined the spatial structure of these species where they co-exist at small spatial scales in the absence of apparent environmental heterogeneity at two sites, testing: whether conspecific aggregation of mussels can occur (using spatial Monte-Carlo tests); the degree of patchiness (using Korcak B patchiness exponent), and whether there was a relationship between percent cover and patchiness. We found that under certain circumstances there is non-random conspecific aggregation, but that in other circumstances there may be random distribution (i.e. the two species are mixed), so that spatial patterns are context-dependent. The relative cover of the species differed between sites, and within each site, the species with higher cover showed low Korcak B values (indicating low patchiness, i.e. the existence of fewer, larger patches), while the less abundant species showed the reverse, i.e. high patchiness. This relationship did not hold for either species within sites. We conclude that co-existence between these mussels is possible, even at small spatial scales because each species is an ecological engineer and, while they have been shown to compete for space, this is preceded by initial facilitation. We suggest that a patchy pattern of co-existence is possible because of a balance between direct (competitive) and indirect (facilitative) interactions. PMID:22132084

  16. Patchiness and co-existence of indigenous and invasive mussels at small spatial scales: the interaction of facilitation and competition.

    PubMed

    Erlandsson, Johan; McQuaid, Christopher D; Sköld, Martin

    2011-01-01

    Ecological theory predicts that two species with similar requirements will fail to show long-term co-existence in situations where shared resources are limiting, especially at spatial scales that are small relative to the size of the organisms. Two species of intertidal mussels, the indigenous Perna perna and the invasive Mytilus galloprovincialis, form mixed beds on the south coast of South Africa in a situation that has been stable for several generations of these species, even though these populations are often limited by the availability of space. We examined the spatial structure of these species where they co-exist at small spatial scales in the absence of apparent environmental heterogeneity at two sites, testing: whether conspecific aggregation of mussels can occur (using spatial Monte-Carlo tests); the degree of patchiness (using Korcak B patchiness exponent), and whether there was a relationship between percent cover and patchiness. We found that under certain circumstances there is non-random conspecific aggregation, but that in other circumstances there may be random distribution (i.e. the two species are mixed), so that spatial patterns are context-dependent. The relative cover of the species differed between sites, and within each site, the species with higher cover showed low Korcak B values (indicating low patchiness, i.e. the existence of fewer, larger patches), while the less abundant species showed the reverse, i.e. high patchiness. This relationship did not hold for either species within sites. We conclude that co-existence between these mussels is possible, even at small spatial scales because each species is an ecological engineer and, while they have been shown to compete for space, this is preceded by initial facilitation. We suggest that a patchy pattern of co-existence is possible because of a balance between direct (competitive) and indirect (facilitative) interactions. PMID:22132084

  17. Does cannibalism of larvae by adults affect settlement and connectivity of mussel populations?

    NASA Astrophysics Data System (ADS)

    Porri, Francesca; Jordaan, Tembisa; McQuaid, Christopher D.

    2008-09-01

    Intertidal population dynamics are driven by a complex series of processes, including larval supply and the possibility of larval predation by benthic animals such as filter-feeders. We hypothesised that cannibalism by adults could play a major role in the population connectivity of mussel populations by removing larvae as they attempt to settle in the adult habitat. Specifically, we tested hypotheses that consumption of mussel larvae by adults removes a significant proportion of potential settlers and is influenced by both settlement intensity and tidal state (flooding or ebbing). Predation of mussel larvae by adult mussels was investigated on incoming and ebbing tides during four spring tides by analysing the gut contents of adult Perna perna and Mytilus galloprovincialis collected from the low intertidal mussel zone between October 2005 and January 2006. Consumption rates were then compared with estimates of successful settler densities on natural beds. The results showed that mortality of competent mussel larvae through adult ingestion removes up to 77% a of potential settlers. Rates of larval consumption were highest during months of intense settlement, suggesting that mussels feed opportunistically, filtering a relatively fixed volume of water and removing particles, including larvae, in proportion to their densities in the water. Rates of larviphagy were also higher during receding than incoming tides. We suggest that this is due to changes in larval density or, more probably, in adult filtration efficiency that are related to the state of the tide. Despite significant effects of both tidal state and settlement intensity on rates of larval ingestion, neither had a significant effect on the proportion of potential settlers removed. During settlement more than half of all potential settlers are lost through cannibalism, with potentially serious consequences for population maintenance. The results highlight the paradoxical nature of the evolution of settlement

  18. Chronic contamination assessment integrating biomarkers' responses in transplanted mussels--a seasonal monitoring.

    PubMed

    Pereira, C D S; Martín-Díaz, M L; Catharino, M G M; Cesar, A; Choueri, R B; Taniguchi, S; Abessa, D M S; Bícego, M C; Vasconcellos, M B A; Bainy, A C D; Sousa, E C P M; Delvalls, T A

    2012-05-01

    This study aimed to provide the first biomonitoring integrating biomarkers and bioaccumulation data in São Paulo coast, Brazil and, for this purpose, a battery of biomarkers of defense mechanisms was analyzed and linked to contaminants' body burden in a weigh-of-evidence approach. The brown mussel Perna perna was selected to be transplanted from a farming area (Caraguatatuba) to four possibly polluted sites: Engenho D'Água, DTCS (Dutos e Terminais do Centro-Oeste de São Paulo) oil terminal (Sao Sebastiao zone), Palmas Island, and Itaipu (It; Santos Bay zone). After 3 months of exposure in each season, mussels were recollected and the cytochrome P4501A (CYP1A)- and CYP3A-like activities, glutathione-S-transferase and antioxidants enzymes (catalase, glutathione peroxidase, and glutathione reductase) were analyzed in gills. The concentrations of polycyclic aromatic hydrocarbons, linear alkylbenzenes, and nonessential metals (Cr, Cd, Pb, and Hg) in whole tissue were also analyzed and data were linked to biomarkers' responses by multivariate analysis (principal component analysis-factor analysis). A representation of estimated factor scores was performed to confirm the factor descriptions and to characterize the studied stations. Biomarkers exhibited most significant alterations all year long in mussels transplanted to It, located at Santos Bay zone, where bioaccumulation of organic and inorganic compounds was detected. This integrated approach using transplanted mussels showed satisfactory results, pointing out differences between sites, seasons, and critical areas, which could be related to land-based contaminants' sources. The influence of natural factors and other contaminants (e.g., pharmaceuticals) on biomarkers' responses are also discussed. PMID:20725937

  19. Mevalonosomes: specific vacuoles containing the mevalonate pathway in Plocamium brasiliense cortical cells (Rhodophyta).

    PubMed

    Paradas, Wladimir Costa; Crespo, Thalita Mendes; Salgado, Leonardo Tavares; de Andrade, Leonardo Rodrigues; Soares, Angélica Ribeiro; Hellio, Claire; Paranhos, Ricardo Rogers; Hill, Lilian Jorge; de Souza, Geysa Marinho; Kelecom, Alphonse Germaine Albert Charles; Da Gama, Bernardo Antônio Perez; Pereira, Renato Crespo; Amado-Filho, Gilberto Menezes

    2015-04-01

    This paper has identified, for the first time in a member of the Rhodophyta, a vacuolar organelle containing enzymes that are involved in the mevalonate pathway-an important step in red algal isoprenoid biosynthesis. These organelles were named mevalonosomes (Mev) and were found in the cortical cells (CC) of Plocamium brasiliense, a marine macroalgae that synthesizes several halogenated monoterpenes. P. brasiliense specimens were submitted to a cytochemical analysis of the activity of the 3-hydroxy-3-methylglutaryl-CoA synthase (HMGS). Using transmission electron microscopy (TEM), we confirmed the presence of HMGS activity within the Mev. Because HMGS is necessary for the biosynthesis of halogenated monoterpenes, we isolated a hexanic fraction (HF) rich in halogenated monoterpenes from P. brasiliense that contained a pentachlorinated monoterpene as a major metabolite. Because terpenes are often related to chemical defense, the antifouling (AF) activity of pentachlorinated monoterpene was tested. We found that the settlement of the mussel Perna perna was reduced by HF treatment (2.25 times less than control; 40% and 90% of fouled surface, respectively; P = 0.001; F9,9 = 1.13). The HF (at 10 μg · mL(-1) ) also inhibited three species of fouling microalgae (Chlorarachnion reptans, Cylindrotheca cloisterium, and Exanthemachrysis gayraliae), while at a higher concentration (50 μg · mL(-1) ), it inhibited the bacteria Halomonas marina, Polaribacter irgensii, Pseudoalteromonas elyakovii, Shewanella putrefaciens, and Vibrio aestuarianus. The AF activity of P. brasiliense halogenated monoterpenes and the localization of HMGS activity inside Mev suggest that this cellular structure found in CC may play a role in thallus protection against biofouling. PMID:26986518

  20. Mitochondrial DNA paradox: sex-specific genetic structure in a marine mussel – despite maternal inheritance and passive dispersal

    PubMed Central

    2012-01-01

    Background When genetic structure is identified using mitochondrial DNA (mtDNA), but no structure is identified using biparentally-inherited nuclear DNA, the discordance is often attributed to differences in dispersal potential between the sexes. Results We sampled the intertidal rocky shore mussel Perna perna in a South African bay and along the nearby open coast, and sequenced maternally-inherited mtDNA (there is no evidence for paternally-inherited mtDNA in this species) and a biparentally-inherited marker. By treating males and females as different populations, we identified significant genetic structure on the basis of mtDNA data in the females only. Conclusions This is the first study to report sex-specific differences in genetic structure based on matrilineally-inherited mtDNA in a passively dispersing species that lacks social structure or sexual dimorphism. The observed pattern most likely stems from females being more vulnerable to selection in habitats from which they did not originate, which also manifests itself in a male-biased sex ratio. Our results have three important implications for the interpretation of population genetic data. First, even when mtDNA is inherited exclusively in the female line, it also contains information about males. For that reason, using it to identify sex-specific differences in genetic structure by contrasting it with biparentally-inherited markers is problematic. Second, the fact that sex-specific differences were found in a passively dispersing species in which sex-biased dispersal is unlikely highlights the fact that significant genetic structure is not necessarily a function of low dispersal potential or physical barriers. Third, even though mtDNA is typically used to study historical demographic processes, it also contains information about contemporary processes. Higher survival rates of males in non-native habitats can erase the genetic structure present in their mothers within a single generation. PMID:22694765

  1. Introduction of the alien Xenostrobus securis (Bivalvia: Mytilidae) into Hong Kong, China: interactions with and impacts upon native species and the earlier introduced Mytilopsis sallei (Bivalvia: Dreissenidae).

    PubMed

    Morton, Brian; Leung, K F

    2015-03-15

    This constitutes the first record of the Australian alien mytilid Xenostrobus securis in China. The introduction occurred prior to 2010 probably via shipping arriving at Yantian in Mirs Bay, China, close to Hong Kong. Point sources of infection could be Australia or Korea or Japan where it has similarly been introduced. Analysis of X. securis in Hong Kong shows that it tolerates a wide range of salinities from 5.4‰ to 28.7‰. Water temperatures in Hong Kong match those in its native range. In Hong Kong, X. securis co-occurs with the similarly introduced Mytilopsis sallei and a native bivalve community. The population structure of X. securis suggests a lifespan of >2 years with new generations produced by conspecifics. Such a life history strategy is also exhibited by M. sallei. Now established in China, northern Asia, the Mediterranean and, most recently, the Iberian Atlantic, the invasion of other locations by X. securis seems probable. PMID:25599632

  2. Habitat Preferences and Growth of Ruditapes bruguieri (Bivalvia: Veneridae) at the Northern Boundary of Its Range

    PubMed Central

    2014-01-01

    This work is the first attempt to study growth and some morphological parameters of the clam Ruditapes bruguieri, as well as its habitat preferences. It is found that R. bruguieri lives on bottom sediments including pebble and coarse- and medium-grained sand with a slight admixture of silt. At the study area, this bivalve inhabits sea waters with good aeration, stable oceanic water salinity, and a high oxygen concentration. The annual fluctuations of the water temperature from 13-14°C (in winter) to 22–29°C (in summer) are close to the threshold temperature values, within which the species can exist. Near the boundary of the species range, along the Jeju Island coasts, south of Republic of Korea, 83.8% of all clams die during the coldest period of the year. Here, annual rings are formed on R. bruguieri shells during winter. The maximum age of R. bruguieri, determined during the study, is 6.5 years, but the clam samples contain mainly individuals at 3.0–3.5 years of age (34%). The largest clam dimensions are 36.0 × 26.5 mm (length × height of shell). At the study area, a usual shell length is 20.0–32.0 mm (75% of all the collected individuals). PMID:24526886

  3. The complete mitogenome of the giant clam Tridacna squamosa (Heterodonta: Bivalvia: Tridacnidae).

    PubMed

    Gan, Han Ming; Gan, Huan You; Tan, Mun Hua; Penny, Shane S; Willan, Richard C; Austin, Christopher M

    2016-09-01

    The complete mitochondrial genome of the commercially and ecologically important and internationally vulnerable giant clam Tridacna squamosa was recovered by genome skimming using the MiSeq platform. The T. squamosa mitogenome has 20,930 base pairs (62.35% A+T content) and is made up of 12 protein-coding genes, 2 ribosomal subunit genes, 24 transfer RNAs, and a 2594 bp non-coding AT-rich region. The mitogenome has a relatively large insertion in the atp6 gene. This is the first mitogenome to be sequenced from the genus Tridacna, and the family Tridacnidae and represents a new gene order. PMID:25648928

  4. The contrasted evolutionary fates of deep-sea chemosynthetic mussels (Bivalvia, Bathymodiolinae)a

    PubMed Central

    Thubaut, Justine; Puillandre, Nicolas; Faure, Baptiste; Cruaud, Corinne; Samadi, Sarah

    2013-01-01

    Bathymodiolinae are giant mussels that were discovered at hydrothermal vents and harboring chemosynthetic symbionts. Due to their close phylogenetic relationship with seep species and tiny mussels from organic substrates, it was hypothesized that they gradually evolved from shallow to deeper environments, and specialized in decaying organic remains, then in seeps, and finally colonized deep-sea vents. Here, we present a multigene phylogeny that reveals that most of the genera are polyphyletic and/or paraphyletic. The robustness of the phylogeny allows us to revise the genus-level classification. Organic remains are robustly supported as the ancestral habitat for Bathymodiolinae. However, rather than a single step toward colonization of vents and seeps, recurrent habitat shifts from organic substrates to vents and seeps occurred during evolution, and never the reverse. This new phylogenetic framework challenges the gradualist scenarios “from shallow to deep.” Mussels from organic remains tolerate a large range of ecological conditions and display a spectacular species diversity contrary to vent mussels, although such habitats are yet underexplored compared to vents and seeps. Overall, our data suggest that for deep-sea mussels, the high specialization to vent habitats provides ecological success in this harsh habitat but also brings the lineage to a kind of evolutionary dead end. PMID:24363902

  5. Oceanographic conditions govern shell growth of Arctica islandica (Bivalvia) in surface waters off Northeast Iceland

    NASA Astrophysics Data System (ADS)

    Marali, Soraya; Schöne, Bernd R.

    2015-04-01

    Shells of the long-lived bivalve Arctica islandica provide absolutely dated, highly resolved archives of environmental variability in the extratropical realm. Shell growth rates of contemporaneous A. islandica specimens are synchronized by one or several environmental factor(s), such as seawater temperature, food supply etc. Based on the growth synchrony, increment width records can be combined to composite chronologies. However, according to existing studies, A. islandica specimens from shallow waters do not show synchronous changes in shell growth and may thus not provide information about environmental conditions such as sea surface temperature. Here, we present the first statistically robust composite chronology of A. islandica from unpolluted surface waters (8-23 m) off Northeast Iceland. The complete record spans the time interval of 1835 to 2012. Times of enhanced shell growth coincide with periods of higher temperature and elevated food supply. Instrumental sea surface temperature (SST) during the growing season explains up to 43% of the variation in relative shell growth. However, the correlation strength varies over time. When the environmental conditions at the sampling site were stable over many consecutive years, i.e. one of the two major surface currents (the warm, nutrient-rich Irminger Current or the cold, nutrient-deficient East Icelandic Current) predominated the area over longer time intervals, the growth synchrony among coeval A. islandica weakened and the correlation between shell growth and SSTs was markedly reduced. Conversely, if the habitat was under the alternating influence of both ocean currents, shell growth was stronger correlated to each other and to SST. Thus, environmental variability is required to synchronize shell growth rates within an A. islandica population. This study further enlightens the relationship between bivalve shell growth and environmental variables.

  6. Organization pattern of nacre in Pteriidae (Bivalvia: Mollusca) explained by crystal competition

    PubMed Central

    Checa, Antonio G; Okamoto, Takashi; Ramírez, Joaquín

    2006-01-01

    Bivalve nacre is a brick-wall-patterned biocomposite of aragonite platelets surrounded by organic matter. SEM–electron back scatter diffraction analysis of nacre of the bivalve family Pteriidae reveals that early aragonite crystals grow with their c-axes oriented perpendicular to the growth surface but have their a- and b-axes disoriented. With the accumulation of successive lamellae, crystals progressively orient themselves with their b-axes mutually parallel and towards the growth direction. We propose that progressive orientation is a result of competition between nacre crystals at the growth front of lamellae, which favours selection of crystals whose fastest growth axis (b-axis) is oriented parallel to the direction of propagation of the lamella. A theoretical model has been developed, which simulates competition of rhombic plates at the lamellar growth front as well as epitaxial growth of crystals onto those of the preceding lamella. The model predicts that disordered nacre progressively produces bivalve-like oriented nacre. As growth fronts become diffuse (as is the common case in bivalves) it takes longer for nacre to become organized. Formation of microdomains of nacre platelets with different orientations is also reproduced. In conclusion, not only the organic matrix component, but also the mineral phase plays an active role in organizing the final microstructure. PMID:16777720

  7. Phylogeny and androgenesis in the invasive Corbicula clams (Bivalvia, Corbiculidae) in Western Europe

    PubMed Central

    2011-01-01

    Background The genus Corbicula is one of the most invasive groups of molluscs. It includes both sexual and androgenetic lineages. The present study re-assessed the different morphotypes and haplotypes of West European Corbicula in order to clarify their taxonomic identification and phylogenetic relationships with American and Asian Corbicula clams. We studied several populations from West European river basins (Meuse, Seine, Rhine and Rhône) through an "integrative taxonomy" approach. We combined morphology, partial mitochondrial COI and cyt b sequences and eleven microsatellite loci. Furthermore, we looked for discrepancies between mtDNA and nrDNA/morphology, indicative of androgenesis between lineages. Results There are three Corbicula morphotypes in Western Europe associated to three mitochondrial lineages and three genotypes. Form R shares the same COI haplotype as the American form A and the Japanese C. leana. Form S and the American form C have the same haplotype, although their morphologies seem divergent. The European form Rlc belongs to the same mitochondrial lineage as both the American form B and the Asian C. fluminea. Interestingly, within each haplotype/genotype or lineage, no genetic diversity was found although their invasive success is high. Moreover, we detected rare mismatches between mtDNA and nrDNA/morphology, indicative of androgenesis and mitochondrial capture between form R and form S and therefore challenging the phylogenetic relatedness and the species status within this genus. The global phylogenetic analysis revealed that the sexual Corbicula lineages seem restricted to the native areas while their androgenetic relatives are widespread and highly invasive. Conclusions We clarified the discrepancies and incongruent results found in the literature about the European morphotypes of Corbicula and associated mitochondrial lineages. The three West European morphotypes belong to three distinct nuclear and mitochondrial lineages. However mitochondrial capture occurs in sympatric populations of forms R and S. The species status of the morphotypes therefore remains doubtful. Moreover the androgenetic lineages seem widely distributed compared to their sexual relatives, suggesting that androgenesis and invasive success may be linked in the genus Corbicula. PMID:21619630

  8. Novel Microsatellite Markers of Meretrix petechialis and Cross-species Amplification in Related Taxa (Bivalvia: Veneroida)

    PubMed Central

    Kang, Jung-Ha; Kim, Byeng-Hak; Park, Jung-Youn; Lee, Jung-Mi; Jeong, Ji-Eun; Lee, Jun-Sang; Ko, Hyun-Sook; Lee, Yong-Seok

    2012-01-01

    The Asian hard clam, Meretrix petechialis, is an economically important bivalve, but its catch and population sizes are decreasing rapidly, owing to many factors, including large-scale reclamation of its natural habitat on the western coast of the Korean peninsula. Attempts to restore the resources and production of this species require genetic structure and diversity information. In this study, we developed 15 microsatellite markers from a partial genomic library enriched in GT repeats. Nine of these markers were polymorphic, with an average allele number of six, and six were monomorphic in 95 tested individuals. No linkage disequilibrium was found between any pair of loci (p > 0.05), and deviations from the Hardy–Weinberg equilibrium (HWE) test showing excess of heterozygotes was observed in only one of nine loci. In addition, no null alleles or genetic differentiation between two tested populations were detected. A cross-species amplification in 12 species of four families resulted in two M. petechialis-specific loci and three possible universal markers. This information will be useful in the future development of high-quality artificial seedlings and sustainable resource management. PMID:23443103

  9. Oocyte Degeneration Associated with Follicle Cells in Female Mactra chinensis (Bivalvia: Mactridae)

    PubMed Central

    Kim, Sung Han; Chung, Ee-Yung; Lee, Ki-Young

    2014-01-01

    Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of follicle cells during oocyte degeneration are associated with phagocytosis and the intracellular digestion of products. In this study, morphologically similar degenerated phagosomes (various lysosomes), which were observed in the degenerated oocytes, appeared in the follicle cells. After the spawning of the oocytes, the follicle cells were involved in oocyte degeneration through phagocytosis by phagolysosomes. Therefore, it can be assumed that follicle cells reabsorb phagosomes from degenerated oocytes. In this study, the presence of lipid granules, which occurred from degenerating yolk granules, gradually increased in degenerating oocytes. The function of follicle cells can accumulate reserves of lipid granules and glycogen in the cytoplasm, which can be employed by the vitellogenic oocyte. Based on observations of follicle cells attached to degenerating oocytes after spawning, the follicle cells of this species are involved in the lysosomal induction of oocyte degeneration for the reabsorption of phagosomes (phagolysosomes) in the cytoplasm for nutrient storage, as seen in other bivalves. PMID:25949203

  10. Intraspecific phylogeography of Lasmigona subviridis (Bivalvia: Unionidae): conservation implications of range discontinuity.

    PubMed

    King, T L; Eackles, M S; Gjetvaj, B; Hoeh, W R

    1999-12-01

    A nucleotide sequence analysis of the first internal transcribed spacer region (ITS-1) between the 5.8S and 18S ribosomal DNA genes (640 bp) and cytochrome c oxidase subunit I (COI) of mitochondrial DNA (mtDNA) (576 bp) was conducted for the freshwater bivalve Lasmigona subviridis and three congeners to determine the utility of these regions in identifying phylogeographic and phylogenetic structure. Sequence analysis of the ITS-1 region indicated a zone of discontinuity in the genetic population structure between a group of L. subviridis populations inhabiting the Susquehanna and Potomac Rivers and more southern populations. Moreover, haplotype patterns resulting from variation in the COI region suggested an absence of gene exchange between tributaries within two different river drainages, as well as between adjacent rivers systems. The authors recommend that the northern and southern populations, which are reproductively isolated and constitute evolutionarily significant lineages, be managed as separate conservation units. Results from the COI region suggest that, in some cases, unionid relocations should be avoided between tributaries of the same drainage because these populations may have been reproductively isolated for thousands of generations. Therefore, unionid bivalves distributed among discontinuous habitats (e.g. Atlantic slope drainages) potentially should be considered evolutionarily distinct. The DNA sequence divergences observed in the nuclear and mtDNA regions among the Lasmigona species were congruent, although the level of divergence in the COI region was up to three times greater. The genus Lasmigona, as represented by the four species surveyed in this study, may not be monophyletic. PMID:10703552

  11. Clarifying phylogenetic relationships and the evolutionary history of the bivalve order Arcida (Mollusca: Bivalvia: Pteriomorphia).

    PubMed

    Combosch, David J; Giribet, Gonzalo

    2016-01-01

    The systematics of the bivalve order Arcida constitutes an unresolved conundrum in bivalve systematics. The current definition of Arcida encompasses two superfamilies: Limopsoidea, which includes the recent families Philobryidae and Limopsidae, and Arcoidea, which encompasses the families Arcidae, Cucullaeidae, Noetiidae, Glycymerididae and Parallelodontidae. This classification, however, is controversial particularly with respect to the position and taxonomic status of Glycymerididae. Previous molecular phylogenies were limited either by the use of only a single molecular marker or by including only a few limopsoid and glycymeridid taxa. The challenging nature of Arcida taxonomy and the controversial results of some of the previous studies, prompted us to use a broad range of taxa (55 species), three nuclear markers (18S rRNA, 28S rRNA and histone H3) and a wide range of algorithmic approaches. This broad but stringent approach led to a number of results that differ significantly from previous studies. We provide the first molecular evidence that supports the separation of Arcoidea from Limopsoidea, although the exact position of Glycymerididae remains unresolved, and the monophyly of Limopsoidea is algorithm-dependent. In addition, we present the first time-calibrated evolutionary tree of Arcida relationships, indicating a significant increase in the diversification of arcidan lineages at the beginning of the Cretaceous, around 140Ma. The monophyly of Arcida, which has been supported previously, was confirmed in all our analyses. Although relationships among families remain somehow unresolved we found support for the monophyly of most arcidan families, at least under some analytical conditions (i.e., Glycymerididae, Noetiidae, Philobryidae, and Limopsidae). However, Arcidae, and particularly Arcinae, remain a major source of inconsistency in the current system of Arcida classification and are in dire need of taxonomic revision. PMID:26427825

  12. Microbial distribution and abundance in the digestive system of five shipworm species (Bivalvia: Teredinidae).

    PubMed

    Betcher, Meghan A; Fung, Jennifer M; Han, Andrew W; O'Connor, Roberta; Seronay, Romell; Concepcion, Gisela P; Distel, Daniel L; Haygood, Margo G

    2012-01-01

    Marine bivalves of the family Teredinidae (shipworms) are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes) of the gills (ctenidia). These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH) and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis). These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose. PMID:23028923

  13. Transfection of eggs in the bivalve mollusc Chamelea gallina (Bivalvia, Veneridae).

    PubMed

    Guerra, R; Esponda, P

    2006-04-01

    Eggs from the bivalve mollusc Chamelea gallina were transfected in vitro. The p-GeneGrip gene construction that expresses the green fluorescent protein (GFP) was employed. It was necessary to remove the jelly coat which covers the egg surface for a successful transfection, and then 44.2% of gametes appeared transfected after using naked DNA. On the other hand, cationic liposomes (Lipofectamine) and neutral lipids (GenePORTER) were employed as gene vectors. After the employ of Lipofectamine 35.6% of eggs were transfected and 41.4% after using GenePORTER. Fluorescence analysis showed that the foreign gene appeared principally located in the egg cytoplasm, but laser confocal microscopy showed that it was also present in the nucleus. Furthermore, PCR analysis demonstrated that the foreign DNA appeared in the DNA extracted from the treated eggs. This simple method for the transfection of mollusc eggs would be interesting for future biotechnological applications in species of commercial interest. PMID:17283962

  14. The influence of salinity on the heat-shock protein response of Potamocorbula amurensis (Bivalvia).

    PubMed

    Werner, Ingeborg

    2004-01-01

    For biomarkers to be useful in assessing anthropogenic impacts in field studies involving aquatic organisms, they should not be affected by naturally occurring changes in environmental parameters such as salinity. This is especially important in estuarine environments and for relatively unspecific biomarkers like heat-shock proteins (hsps, stress proteins). In this study, the heat-shock protein response was measured in the euryhaline clam, Potamocorbula amurensis, after exposure to a range of salinities reflecting normal and extreme environmental conditions in Northern San Francisco Bay, California. The ability to raise cellular hsp70 levels in response to heat-shock was significantly impaired in P. amurensis collected from a low (0.5 ppt) salinity field site, and after 14 day exposure to low salinity in the laboratory. PMID:15178117

  15. Microbial Distribution and Abundance in the Digestive System of Five Shipworm Species (Bivalvia: Teredinidae)

    PubMed Central

    Betcher, Meghan A.; Fung, Jennifer M.; Han, Andrew W.; O’Connor, Roberta; Seronay, Romell; Concepcion, Gisela P.; Distel, Daniel L.; Haygood, Margo G.

    2012-01-01

    Marine bivalves of the family Teredinidae (shipworms) are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes) of the gills (ctenidia). These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH) and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis). These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose. PMID:23028923

  16. Using DNA barcoding to differentiate invasive Dreissena species (Mollusca, Bivalvia)

    PubMed Central

    Marescaux, Jonathan; Van Doninck, Karine

    2013-01-01

    Abstract The zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena rostriformis bugensis) are considered as the most competitive invaders in freshwaters of Europe and North America. Although shell characteristics exist to differentiate both species, phenotypic plasticity in the genus Dreissena does not always allow a clear identification. Therefore, the need to find an accurate identification method is essential. DNA barcoding has been proven to be an adequate procedure to discriminate species. The cytochrome c oxidase subunit I mitochondrial gene (COI) is considered as the standard barcode for animals. We tested the use of this gene as an efficient DNA barcode and found that it allow rapid and accurate identification of adult Dreissena individuals. PMID:24453560

  17. Using DNA barcoding to differentiate invasive Dreissena species (Mollusca, Bivalvia).

    PubMed

    Marescaux, Jonathan; Van Doninck, Karine

    2013-12-30

    The zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena rostriformis bugensis) are considered as the most competitive invaders in freshwaters of Europe and North America. Although shell characteristics exist to differentiate both species, phenotypic plasticity in the genus Dreissena does not always allow a clear identification. Therefore, the need to find an accurate identification method is essential. DNA barcoding has been proven to be an adequate procedure to discriminate species. The cytochrome c oxidase subunit I mitochondrial gene (COI) is considered as the standard barcode for animals. We tested the use of this gene as an efficient DNA barcode and found that it allow rapid and accurate identification of adult Dreissena individuals. PMID:24453560

  18. Biology and Population Dynamics of Donax trunculus L. (Bivalvia: Donacidae) in the South Adriatic Coast (Italy)

    NASA Astrophysics Data System (ADS)

    Zeichen, M. Manca; Agnesi, S.; Mariani, A.; Maccaroni, A.; Ardizzone, G. D.

    2002-06-01

    Biology and population dynamics of the suspension-feeding wedge clam Donax trunculus (Linnaeus, 1758) were studied for 13 months (November 1994-April 1996) along the Italian Southern Adriatic coast near the Lagoon of Lesina. Specimens were found at depths between 0 and 2 m, mainly in fine grain bottoms. The spatial coastal distribution showed an intraspecific segregation between young and adult wedge clams. A unimodal recruitment (length >4 mm) occurred in winter (December-February). Length frequency distributions were used to determine age and growth rate. Three year classes were regularly observed and their growth pattern defined. The population showed a maximum length of 37 mm and a longevity of 4 years. Analysis of seasonal variations in the reproductive cycle showed that gametogenesis occurred in spring in females. After the spawning season (March-July) females of D. trunculus remained in a resting stage from August to January.

  19. Lifespan, growth rate, and body size across latitude in marine Bivalvia, with implications for Phanerozoic evolution.

    PubMed

    Moss, David K; Ivany, Linda C; Judd, Emily J; Cummings, Patrick W; Bearden, Claire E; Kim, Woo-Jun; Artruc, Emily G; Driscoll, Jeremy R

    2016-08-17

    Mean body size in marine animals has increased more than 100-fold since the Cambrian, a discovery that brings to attention the key life-history parameters of lifespan and growth rate that ultimately determine size. Variation in these parameters is not well understood on the planet today, much less in deep time. Here, we present a new global database of maximum reported lifespan and shell growth coupled with body size data for 1 148 populations of marine bivalves and show that (i) lifespan increases, and growth rate decreases, with latitude, both across the group as a whole and within well-sampled species, (ii) growth rate, and hence metabolic rate, correlates inversely with lifespan, and (iii) opposing trends in lifespan and growth combined with high variance obviate any demonstrable pattern in body size with latitude. Our observations suggest that the proposed increase in metabolic activity and demonstrated increase in body size of organisms over the Phanerozoic should be accompanied by a concomitant shift towards faster growth and/or shorter lifespan in marine bivalves. This prediction, testable from the fossil record, may help to explain one of the more fundamental patterns in the evolutionary and ecological history of animal life on this planet. PMID:27488653

  20. Molecular Cytogenetics in Trough Shells (Mactridae, Bivalvia): Divergent GC-Rich Heterochromatin Content.

    PubMed

    García-Souto, Daniel; Pérez-García, Concepción; Kendall, Jack; Pasantes, Juan J

    2016-01-01

    The family Mactridae is composed of a diverse group of marine organisms, commonly known as trough shells or surf clams, which illustrate a global distribution. Although this family includes some of the most fished and cultured bivalve species, their chromosomes are poorly studied. In this work, we analyzed the chromosomes of Spisula solida, Spisula subtruncata and Mactra stultorum by means of fluorochrome staining, C-banding and fluorescent in situ hybridization using 28S ribosomal DNA (rDNA), 5S rDNA, H3 histone gene and telomeric probes. All three trough shells presented 2n = 38 chromosomes but different karyotype compositions. As happens in most bivalves, GC-rich regions were limited to the nucleolus organizing regions in Spisula solida. In contrast, many GC-rich heterochromatic bands were detected in both Spisula subtruncata and Mactra stultorum. Although the three trough shells presented single 5S rDNA and H3 histone gene clusters, their chromosomal locations differed. Regarding major rDNA clusters, while Spisula subtruncata presented a single cluster, both Spisula solida and Mactra stultorum showed two. No evidence of intercalary telomeric signals was detected in these species. The molecular cytogenetic characterization of these taxa will contribute to understanding the role played by chromosome changes in the evolution of trough shells. PMID:27537915

  1. Comparative Large-Scale Mitogenomics Evidences Clade-Specific Evolutionary Trends in Mitochondrial DNAs of Bivalvia

    PubMed Central

    Plazzi, Federico; Puccio, Guglielmo; Passamonti, Marco

    2016-01-01

    Despite the figure of complete bivalve mitochondrial genomes keeps growing, an assessment of the general features of these genomes in a phylogenetic framework is still lacking, despite the fact that bivalve mitochondrial genomes are unusual under different aspects. In this work, we constructed a dataset of one hundred mitochondrial genomes of bivalves to perform the first systematic comparative mitogenomic analysis, developing a phylogenetic background to scaffold the evolutionary history of the class' mitochondrial genomes. Highly conserved domains were identified in all protein coding genes; however, four genes (namely, atp6, nad2, nad4L, and nad6) were found to be very divergent for many respects, notwithstanding the overall purifying selection working on those genomes. Moreover, the atp8 gene was newly annotated in 20 mitochondrial genomes, where it was previously declared as lacking or only signaled. Supernumerary mitochondrial proteins were compared, but it was possible to find homologies only among strictly related species. The rearrangement rate on the molecule is too high to be used as a phylogenetic marker, but here we demonstrate for the first time in mollusks that there is correlation between rearrangement rates and evolutionary rates. We also developed a new index (HERMES) to estimate the amount of mitochondrial evolution. Many genomic features are phylogenetically congruent and this allowed us to highlight three main phases in bivalve history: the origin, the branching of palaeoheterodonts, and the second radiation leading to the present-day biodiversity. PMID:27503296

  2. Reproductive Cycle of Hard Clam, Meretrix lyrata Sowerby, 1851 (Bivalvia: Veneridae) from Sarawak, Malaysia

    PubMed Central

    Hamli, Hadi; Idris, Mohd Hanafi; Rajaee, Amy Halimah; Kamal, Abu Hena Mustafa

    2015-01-01

    A study of the reproductive cycle of the hard clam, Meretrix lyrata, was documented based on histological observation and Gonad Index (GI). Samples were taken from estuarine waters of the Buntal River in Sarawak, Malaysia. The gonad of M. lyrata started to develop in September 2013. Gametogenesis continued to develop until the maturation and spawning stage from February to April 2014. The GI pattern for a one-year cycle showed a significant correlation with chlorophyll a. The corresponding GI with chlorophyll a suggested that the development of the reproductive cycle of M. lyrata required a high amount of food to increase gametogenesis. PMID:26868710

  3. The unionid (Bivalvia) fauna of the Sipsey River in northwestern Alabama, an aquatic hotspot

    USGS Publications Warehouse

    McCullagh, W.H.; Williams, J.D.; McGregor, S.W.; Pierson, J.M.; Lydeard, C.

    2002-01-01

    Recent surveys for unionid bivalves were conducted in the mainstem of the Sipsey River and headwater tributaries (Tombigbee River drainage) during the summer and autumn of 1996-1999. A total of 35 species and 22 genera were found. Museum records from the upper Sipsey, based largely on the efforts of H. H. Smith during 1910-11, raised the total number of recorded unionids in the Sipsey to 42. Smith documented 25 species in the river; however, most of his collections were made in the mid- to upper-Sipsey, which has lower diversity. The three most common recently observed species in descending order of abundance were Quadrula asperata (I. Lea, 1861), Pleurobema decisum (I. Lea, 1831), and Tritogonia verrucosa (Rafinesque, 1820). Federally listed species observed recently include Lampsilis perovalis (Conrad, 1834) (threatened), Medionidus acutissimus (I. Lea, 1831) (threatened), P. decisum (endangered), P. perovatum (Conrad, 1834) (endangered), and Potamilus inflatus (I. Lea, 1831) (threatened). Species not observed recently but recorded in prior surveys include Anodontoides radiatus (Conrad, 1834), Arcidens confragosus (Say, 1829), Plectomerus dombeyanus (Valenciennes, 1827), Q. metanevra (Rafinesque, 1820), Q. stapes (I. Lea, 1831) (federally endangered), P. taitianum (I. Lea, 1834) (federally endangered), and Toxolasma parvus (Barnes, 1823). Many, species are known recently or historically by only five or fewer recorded specimens including: A. radiatus, Elliptio arctata (Conrad, 1834), Ligumia recta (Lamarck, 1819), P. taitianum, P. inflatus, Q. aspera (Lea, 1831), Q. metanevra, Q. stapes, T. parvus, Truncilla donaciformis (I. Lea, 1828), Uniomerus tetralasmus (Say, 1831), Utterbackia imbecillis (Say, 1829), A. confragosus, and P. dombeyanus. Unlike the mussel fauna of most Alabama streams, that of the Sipsey River is still relatively intact in terms of species richness despite impacts from mining, silvicultural, and agricultural activities. A concerted effort should be made to provide guidelines to manage floodplain and watershed activities to avoid future adverse impacts on this aquatic hotspot.

  4. The families Carditidae and Condylocardiidae in the Magellan and Perú-Chile provinces (Bivalvia: Carditoidea).

    PubMed

    Güller, Marina; Zelaya, Diego G

    2013-01-01

    Based on the study of available types and extant collections, this paper provides a systematic revision of the living species of Carditoidea occurring in the Magellan and Perú-Chile Provinces. Out of the 19 nominal species reported for the area, eight species are recognized as valid: Cyclocardia compressa, C. spurca, C. thouarsii, C. velutina, Carditella naviformis, C. semen, C. tegulata and Carditopsis flabellum. Other eight nominal species are regarded as synonyms: Cardita magellanica of Cyclocardia velutina; Carditella pallida of C. tegulata; Cardita australis and Actinobolus philippi of Carditella naviformis; Cardium pygmaeum of Carditella semen; Cardita paeteliana of Cyclocardia spurca; Carditella pallida duodecimcostata of Carditopsis flabellum; and Cardita congelascens of Cyclocardia thouarsii. Furthermore, Cardita malvinae and Cardium parvulum are nomina dubia, and the occurrence of Carditella exulata in Magellanic waters is doubtful. PMID:25243284

  5. Ultrastructure of the spermatogenesis of the cockle Anadara granosa L. (Bivalvia: Arcidae)

    NASA Astrophysics Data System (ADS)

    Suwanjarat, J.

    1999-11-01

    In this paper spermatogenesis and sperm ultrastructure of the cockle Anadara granosa are studied using transmission electron microscopy. The spermatocyte presents electron-dense vesicles and the arising axoneme that begins to form the flagellum. During spermatid differentiation, proacrosomal vesicles appear to migrate towards the presumptive anterior pole of the nucleus; eventually these vesicles become acrosome. The spermatozoon of Anadara granosa is of the primitive type. The acrosome, situated at the apex of the nucleus, is cap-shaped and deeply invaginated at the inner side. The spherical nucleus of the spermatozoon contains dense granular chromatin and shows invagination at the posterior poles. The centriole shows the classic nine triplets of microtubules. The middle piece consists of the centriolar complex surrounded by five giant mitochondria. It is shown that the ultrastructure of spermatozoa and spermiogenesis of Anadara granosa reveals a number of features that are common among bivalves.

  6. Expression of glutamine synthetase in Tegillarca granosa (Bivalvia, Arcidae) hemocytes stimulated by Vibrio parahaemolyticus and lipopolysaccharides.

    PubMed

    Bao, Y B; Li, L; Ye, M X; Dong, Y H; Jin, W X; Lin, Z H

    2013-01-01

    The blood cockle, Tegillarca granosa, is a widely consumed clam in the Indo-Pacific region. Glutamine synthetase (GS) is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine. We identified the GS of T. granosa (Tg-GS) from hemocytes by 3'- and 5'-rapid amplification of cDNA ends (RACE)-PCR. The full-length cDNA consisted of 1762 bp, with a 1104-bp open reading frame encoding 367 amino acids. Sequence comparison showed that Tg-GS has homology to GS of other organisms, with 79.78% identity with GS from the Pacific oyster Crassostrea gigas, 71.98% identity with GS from the zebrafish Danio rerio, and 68.96% identity with human Homo sapiens GS. A C-beta-Grasp domain and an N-catalytic domain were identified in Tg-GS, indicating that Tg-GS should be classified as a new member of the GS family. A quantitative RT-PCR assay was used to detect mRNA expression of Tg-GS in five different tissues. Higher levels of mRNA expression of GS were detected in the tissues of hemocytes and the mantle. Up-regulation of GS by challenge with the bacteria Vibrio parahaemolyticus and with bacterial wall lipopolysaccharides showed that GS plays a role in anti-bacterial immunity. We conclude that pathogen infection significantly induces expression level of Tg- GS, and that activation of GS influences the immune response of T. granosa by increasing glutamine concentration. PMID:23661439

  7. Physiological responses of the European cockle Cerastoderma edule (Bivalvia: Cardidae) as indicators of coastal lagoon pollution.

    PubMed

    Nilin, Jeamylle; Pestana, João Luís Teixeira; Ferreira, Nuno Gonçalo; Loureiro, Susana; Costa-Lotufo, Letícia Veras; Soares, Amadeu M V M

    2012-10-01

    Physiological responses can be used as effective parameters to identify environmentally stressful conditions. In this study, physiology changes such as oxygen consumption, clearance rate, survival in air, condition index and energy reserves were measured on natural populations of cockles collected from different sites at Ria de Aveiro, Portugal. At those sites, sediment samples were collected for Hg concentration analysis. Cockles were used for the evaluation of both the Hg concentration and physiological response. Mercury was detected in the cockle tissue and in the sediment collected from the sampling points both nearby and distant from the main mercury contamination source. The energy content was negatively correlated with both Hg concentration in cockle tissues and survival in air. Nonetheless, the energy content was positively correlated with the condition index, and there was a positive correlation between the survival in air test and the tissue mercury concentration. A PCA-factor analysis explained 86.8% of the total variance. The principal factor (62.7%) consisted of the air survival, the Hg in soft tissues (positive) and the condition index (negative). The second factor (24.1%) consisted of a negative correlation between the oxygen consumption and the clearance rate. Due to their sensitivity to environmental conditions, the physiological responses of cockles can be used to assess the ecological status of aquatic environments. More effort should be invested in investigating the effects of environmental perturbations on cockle health once they are a good reporter organism. PMID:22846762

  8. Complete sequence and polymorphisms of female Ruditapes philippinarum (Mollusca: Bivalvia) mitochondria genome.

    PubMed

    Hwang, Jae Yeon; Han, Geon Goo; Park, Jung Youn; Kim, Eun-Mi; An, Cheul Min; Kang, Jung-Ha; Choi, Yun-Jaie; Kim, Eun Bae

    2016-09-01

    Mitogenome of female Ruditapes philippinarum organism was sequenced, and genomic variation and phylogeny were examined in this study. Length of the mitogenome was 22 089 bp showing 94.28% of sequence identity with previously reported sequence. Total 707 single nucleotide polymorphisms, SNPs, were detected and 50 residues were non-synonymous SNPs among the 202 SNPs in protein-coding genes. Deleted genomic fragments with of 265 bp and 322 bp were observed in non-coding regions, ND2 to ND4L and ND4L to tRNA(Ile), respectively. Phylogenic analysis confirmed that used organisms were female R. philippinarum, and the species has closer evolutionary distance with genus Paphia rather than genus Meretrix. Our finding will be help to set an insight for population and evolutionary genomics of Veneroida clams as well as application to marine industry. PMID:26248000

  9. Chlorine toxicity to early life stages of freshwater mussels (Bivalvia: Unionidae)

    USGS Publications Warehouse

    Valenti, T.W.; Cherry, D.S.; Currie, R.J.; Neves, R.J.; Jones, J.W.; Mair, R.; Kane, C.M.

    2006-01-01

    Chlorine (Cl) is a highly toxic, widely used halogen disinfectant that is present in point-source pollution discharges from wastewater treatment plants and industrial facilities. The U.S. Environmental Protection Agency freshwater criteria for Cl are 19 ??g total residual Cl (TRC)/L as a maximum 1-h average concentration and 11 ??g TRC/L as a maximum 4-d average; however, toxicological data for unionids were not used in these calculations. To address this void in the data, we conducted acute tests with glochidia from several species and 21-d bioassays with three-month-old Epioblasma capsaeformis and three-, six-, and 12-month-old Villosa iris juveniles. The 24-h lethal concentration 50 values for glochidia were between 70 and 220 ??g TRC/L, which are 2.5 to 37 times higher than those reported in other studies for cladocerans. Significant declines in growth and survivorship were observed in the 21-d test with E. capsaeformis at 20 ??g TRC/L. Lowest-observed-adverse- effects concentrations in bioassays with juvenile V. iris were higher (30-60 ??g TRC/L) but showed a significant trend of declining toxicity with increased age. Although endpoints were above water quality criteria, the long life spans of unionids and potential implications of chronic exposure to endangered juvenile mussels still warrant concern. ?? 2006 SETAC.

  10. Seawater temperature and salinity controls on Li/Ca ratios in Mytilus edulis (bivalvia) shells

    NASA Astrophysics Data System (ADS)

    Clarke, L. J.; Wanamaker, A. D., Jr.; Kreutz, K. J.; Borns, H. W., Jr.; Introne, D. S.

    2009-04-01

    In this study we have investigated the effects of seawater temperature and salinity on Li/Ca ratios in newly precipitated shell calcite in Mytilus edulis shells, since this potential temperature proxy has not been widely applied beyond brachiopods and inorganic calcite. Juvenile specimens of M. edulis collected from western Greenland were cultured in laboratory aquaria using a four-by-three factorial design that consisted of four circulating temperature baths and three salinities. New shell growth precipitated during the constrained culturing experiment was identified carefully and subsequently dissected from the shells. Following acid dissolution, Li/Ca ratios were measured by ICP-MS, enabling an assessment of temperature and salinity controls on shell Li/Ca ratios. Furthermore, measurement of Li/Ca ratios in the aquaria seawaters has enabled calculation of Li/Ca ratio partition coefficients and direct comparison to Li/Ca ratio to temperature relationships observed for brachiopods and inorganic calcite. The results of this study suggest that bivalve shell Li/Ca ratios can be used as a new temperature proxy.