RESUMO
Early marine invertebrates like the Branchiopoda began their sojourn into dilute media some 500 million years ago in the Middle Cambrian. Others like the Mollusca, Annelida, and many crustacean taxa have followed, accompanying major marine transgressions and regressions, shifting landmasses, orogenies, and glaciations. In adapting to these events and new habitats, such invertebrates acquired novel physiological abilities that attenuate the ion loss and water gain that constitute severe challenges to life in dilute media. Among these taxon-specific adaptations, selected from the subcellular to organismal levels of organization, and constituting a feasible evolutionary blueprint for invading freshwater, are reduced body permeability and surface (S) to volume (V) ratios, lowered osmotic concentrations, increased osmotic gradients, increased surface areas of interface epithelia, relocation of membrane proteins in ion-transporting cells, and augmented transport enzyme abundance, activity, and affinity. We examine these adaptations in taxa that have penetrated into freshwater, revealing diversified modifications, a consequence of distinct body plans, morpho-physiological resources, and occupation routes. Contingent on life history and reproductive strategy, numerous patterns of osmotic regulation have emerged, including intracellular isosmotic regulation in weak hyper-regulators and well-developed anisosmotic extracellular regulation in strong hyper-regulators, likely reflecting inertial adaptations to early life in an estuarine environment. In this review, we address osmoregulation in those freshwater invertebrate lineages that have successfully invaded this biotope. Our analyses show that across 66 freshwater invertebrate species from six phyla/classes that have transmuted into freshwater from the sea, hemolymph osmolalities decrease logarithmically with increasing S:V ratios. The arthropods have the highest osmolalities, from 300 to 650 mOsmoles/kg H2O in the Decapoda with 220-320 mOsmoles/kg H2O in the Insecta; osmolalities in the Annelida range from 150 to 200 mOsmoles/kg H2O, and the Mollusca showing the lowest osmolalities at 40-120 mOsmoles/kg H2O. Overall, osmolalities reach a cut-off at â¼200 mOsmoles/kg H2O, independently of increasing S:V ratio. The ability of species with small S:V ratios to maintain large osmotic gradients is mirrored in their putatively higher Na+/K+-ATPase activities that drive ion uptake processes. Selection pressures on these morpho-physiological characteristics have led to differential osmoregulatory abilities, rendering possible the conquest of freshwater while retaining some tolerance of the ancestral medium.
Assuntos
Água Doce , Osmorregulação , Animais , Evolução Biológica , Crustáceos/metabolismo , Moluscos/metabolismo , Osmorregulação/fisiologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Equilíbrio Hidroeletrolítico/fisiologiaRESUMO
Triterpenoid biosynthesis is generally anaerobic in bacteria and aerobic in Eukarya. The major class of triterpenoids in bacteria, the hopanoids, is different to that in Eukarya, the lanostanoids, and their 4,4,14-demethylated derivatives, sterols. In the deep sea, the prokaryotic contribution to primary productivity has been suggested to be higher because local environmental conditions prevent classic photosynthetic processes from occurring. Sterols have been used as trophic biomarkers because primary producers have different compositions, and they are incorporated in primary consumer tissues. In the present study, we inferred food supply to deep sea, sponges, cnidarians, mollusks, crustaceans, and echinoderms from euphotic zone production which is driven by phytoplankton eukaryotic autotrophy. Sterol composition was obtained by gas chromatography and mass spectrometry. Moreover, we compared the sterol composition of three phyla (i.e., Porifera, Cnidaria, and Echinodermata) collected between a deep and cold-water region and a shallow tropical area. We hypothesized that the sterol composition of shallow tropical benthic organisms would better reflect their photoautotrophic sources independently of the taxonomy. Shallow tropical sponges and cnidarians from environments showed plant and zooxanthellae sterols in their tissues, while their deep-sea counterparts showed phytoplankton and zooplankton sterols. In contrast, echinoids, a class of echinoderms, the most complex phylum along with hemichordates and chordates (deuterostomes), did not show significant differences in their sterol profile, suggesting that cholesterol synthesis is present in deuterostomes other than chordates.
Assuntos
Artrópodes/metabolismo , Cnidários/metabolismo , Equinodermos/metabolismo , Moluscos/metabolismo , Poríferos/metabolismo , Esteróis/metabolismo , Animais , Oceano Atlântico , Dieta , Ecossistema , Cromatografia Gasosa-Espectrometria de Massas , Golfo do México , Especificidade da Espécie , Esteróis/isolamento & purificaçãoRESUMO
Scientists are currently faced with the challenge of assessing the effects of anthropogenic stressors on aquatic ecosystems. Cellular stress response (CSR) biomarkers are ubiquitous and phylogenetically conserved among metazoans and have been successfully applied in environmental monitoring but they can also vary according to natural biotic and abiotic factors. The reported variability may thus limit the wide application of biomarkers in monitoring, imposing the need to identify variability levels in the field. Our aim was to carry out a comprehensive in situ assessment of the CSR (heat shock protein 70â¯kDa, ubiquitin, antioxidant enzymes) and oxidative damage (lipid peroxidation) in wild populations across marine taxa by collecting fish, crustaceans, mollusks and cnidarians during two different seasons (spring and summer) and two habitat types (coast and estuary). CSR end-point patterns were different between taxa with mollusks having higher biomarker levels, followed by the cnidarians, while fish and crustaceans showed lower biomarker levels. The PCA showed clear clusters related to mobility/sessile traits with sessile organisms showing greater levels (>2-fold) of CSR proteins and oxidative damage. Mean intraspecific variability in the CSR measured by the coefficient of variation (% CV) (including data from all seasons and sites) was elevated (35-94%). Overall, there was a seasonal differentiation in biomarker patterns across taxonomic groups, especially evident in fish and cnidarians. A differentiation in biomarker patterns between habitat types was also observed and associated with phenotypic plasticity or local adaptation. Overall, specimens collected in the estuary had lower biomarker levels when compared to specimens collected in the coast. This work highlights the importance of assessing baseline biomarker levels across taxa, seasons and habitats prior to applying biomarker analyses in environmental monitoring. Selecting bioindicator species, defining sampling strategies, and identifying confounding factors are crucial preliminary steps that ensure the success of biomarkers as powerful tools in biomonitoring.
Assuntos
Organismos Aquáticos/classificação , Monitoramento Ambiental/métodos , Estresse Oxidativo/efeitos dos fármacos , Estações do Ano , Espécies Sentinelas/classificação , Poluentes Químicos da Água/análise , Animais , Organismos Aquáticos/efeitos dos fármacos , Argentina , Biomarcadores/análise , Cnidários/efeitos dos fármacos , Cnidários/metabolismo , Crustáceos/efeitos dos fármacos , Crustáceos/metabolismo , Ecossistema , Peixes/metabolismo , Moluscos/efeitos dos fármacos , Moluscos/metabolismo , Espécies Sentinelas/metabolismo , Poluentes Químicos da Água/toxicidadeRESUMO
Electronic paramagnetic resonance (EPR) is an appropriate tool to identify free radicals formed in tissues under normal as well as stressful conditions. Since nitric oxide (NO) as a free radical has paramagnetic properties it can be detected by EPR. The use of spin traps highly improves the sensitivity allowing NO identification, detection and quantification at room temperature in vitro and in vivo conditions. NO production in animals is almost exclusively associated to an enzyme family known as Nitric Oxide Synthases (NOSs). The digestive glands of mollusks are a major target for oxidative disruption related to environmental stress. A simple EPR-methodology to asses both, the presence of NO and its rate of generation in tissues from different mollusk species, is reported here.
Assuntos
Espectroscopia de Ressonância de Spin Eletrônica , Moluscos/metabolismo , Óxido Nítrico/análise , Animais , Oxirredução , Estresse Oxidativo , Espécies Reativas de Nitrogênio/análise , Espécies Reativas de Oxigênio/análiseRESUMO
Despite the many publications concerning the isolation of substances and the many reviews of marine natural products, some groups of organisms remain poorly studied, including "Polychaeta". In response, this review covers articles published through December 2016 that address marine natural products produced from polychaetes, with a focus on antipredatory strategies, competitors, fouling, and pathogens. A total of 121 compounds were isolated from 1934 to 2016, which includes halogenated aromatics, proteins, amino acids and Lumazine derivatives most notably-with a defensive function were found in the literature, most frequently in the families Sabellidae, Terebellidae, Glyceridae, and Nereididae. The period of highest discovery of natural products in defensive actions for the group was the 2000s. Polychaetes were addressed in 26 revisions of the total 51 articles analyzed and are less reported than other marine invertebrates such as sponges, cnidarians, mollusks, and tunicates. In sum, the present review provides a basis for future research on the marine chemical ecology of polychaetes.
Assuntos
Organismos Aquáticos/química , Produtos Biológicos/química , Animais , Organismos Aquáticos/metabolismo , Produtos Biológicos/isolamento & purificação , Cnidários/química , Cnidários/metabolismo , Comportamento Consumatório/fisiologia , Equinodermos/química , Equinodermos/metabolismo , Fenômenos Ecológicos e Ambientais , Moluscos/química , Moluscos/metabolismo , Urocordados/química , Urocordados/metabolismoRESUMO
Despite the increasing impact of heavy metal pollution in southern Mexico due to urban growth and agricultural and petroleum activities, few studies have focused on the behavior and relationships of these pollutants in the biotic and abiotic components of aquatic environments. Here, we studied the bioaccumulation of heavy metals (Cd, Cr, Ni, Pb, V, Zn) in suspended load, sediment, primary producers, mollusks, crustaceans, and fish, in a deltaic lagoon habitat in the Tabasco coast, with the aim to assess the potential ecological risk in that important wetland. Zn showed the highest concentrations, e.g., in suspended load (mean of 159.58 mg kg(-1)) and aquatic consumers (15.43-171.71 mg kg(-1)), particularly Brachyura larvae and ichthyoplankton (112.22-171.71 mg kg(-1)), followed by omnivore Callinectes sp. crabs (113.81-128.07 mg kg(-1)). The highest bioconcentration factors (BCF) of Zn were observed for planktivore and omnivore crustaceans (3.06-3.08). Zn showed a pattern of distribution in the food web through two pathways: the pelagic (where the higher concentrations were found), and the benthic (marsh plants, sediment, mollusk, fish). The other heavy metals had lower occurrences in the food web. Nevertheless, high concentrations of Ni and Cr were found in phytoplankton and sediment (37.62-119.97 mg kg(-1)), and V in epiphytes (68.64 mg kg(-1)). Ni, Cr, and Cd concentrations in sediments surpassed international and national threshold values, and Cd entailed a "considerable" potential risk. These heavy metals are most likely transferred into the food web up to fishes through the benthic pathway. Most of the collected fishes are residents in this type of habitat and have commercial importance. Our results show that the total potential ecological risk in the area can be considered as "moderate". Nevertheless, heavy metal values were similar or surpassed the values from other highly industrialized tropical coastal regions.
Assuntos
Cadeia Alimentar , Metais Pesados/farmacocinética , Poluentes Químicos da Água/farmacocinética , Agricultura , Animais , Monitoramento Ambiental/métodos , Peixes/metabolismo , Metais Pesados/análise , México , Moluscos/metabolismo , Poluentes Químicos da Água/análise , Áreas AlagadasRESUMO
One of the largest detriments in the abalone aquaculture industry is the inherently low growth rate of this marine gastropod. In order to confront this issue, greater molecular knowledge is needed on growth traits. Therefore, transcriptome analyses were performed using RNA-Seq for groups of California red abalones (Haliotis rufescens) cultured under the same conditions, but with high growth rates (HGR) or low growth rates (LGR). De novo assembly generated 44312 contigs used as references for RNA-Seq analysis. Results showed a total of 1437 differentially expressed contigs, among which, 435 were up-regulated in the HGR group and 1002 in LGR individuals. Overall, LGR abalones evidenced a greater number of exclusive transcripts and differentially transcribed genes. These results provide a valuable resource of novel transcripts in this species and further understandings of the molecular bases regulating growth traits in H. rufescens.
Assuntos
Moluscos/genética , Moluscos/metabolismo , Técnicas de Amplificação de Ácido Nucleico , RNA/metabolismo , Transcriptoma , Animais , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas/genética , Proteínas/metabolismo , RNA/genética , Regulação para CimaRESUMO
Antimicrobial peptides form part of the first line of defense against pathogens for many organisms. Current treatments for fungal infections are limited by drug toxicity and pathogen resistance. Cm-p5 (SRSELIVHQRLF), a peptide derived from the marine mollusk Cenchritis muricatus peptide Cm-p1, has a significantly increased fungistatic activity against pathogenic Candida albicans (minimal inhibitory concentration, 10 µg/ml; EC50, 1.146 µg/ml) while exhibiting low toxic effects against a cultured mammalian cell line. Cm-p5 as characterized by circular dichroism and nuclear magnetic resonance revealed an α-helical structure in membrane-mimetic conditions and a tendency to random coil folding in aqueous solutions. Additional studies modeling Cm-p5 binding to a phosphatidylserine bilayer in silico and isothermal titration calorimetry using lipid monophases demonstrated that Cm-p5 has a high affinity for the phospholipids of fungal membranes (phosphatidylserine and phosphatidylethanolamine), only moderate interactions with a mammalian membrane phospholipid, low interaction with ergosterol, and no interaction with chitin. Adhesion of Cm-p5 to living C. albicans cells was confirmed by fluorescence microscopy with FITC-labeled peptide. In a systemic candidiasis model in mice, intraperitoneal administration of Cm-p5 was unable to control the fungal kidney burden, although its low amphiphaticity could be modified to generate new derivatives with improved fungicidal activity and stability.
Assuntos
Antifúngicos/farmacologia , Gastrópodes/metabolismo , Moluscos/metabolismo , Peptídeos/farmacologia , Animais , Candida albicans/efeitos dos fármacos , Candidíase/tratamento farmacológico , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Dicroísmo Circular/métodos , Feminino , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana/métodos , Fosfatidiletanolaminas/metabolismo , Fosfatidilserinas/metabolismo , Fosfolipídeos/metabolismo , Estrutura Secundária de ProteínaRESUMO
The red abalone Haliotis rufescens is one of the most important species for aquaculture in Baja California, México, and despite this, few gene expression studies have been done in tissues such as gill, head and gonad. For this purpose, reverse transcription and quantitative real time PCR (RT-qPCR) is a powerful tool for gene expression evaluation. For a reliable analysis, however, it is necessary to select and validate housekeeping genes that allow proper transcription quantification. Stability of nine housekeeping genes (ACTB, BGLU, TUBB, CY, GAPDH, HPRTI, RPL5, SDHA and UBC) was evaluated in different tissues of red abalone (gill, head and gonad/digestive gland). Four-fold serial dilutions of cDNA (from 25 ngµL(-1) to 0.39 ngµL(-1)) were used to prepare the standard curve, and it showed gene efficiencies between 0.95 and 0.99, with R(2)=0.99. geNorm and NormFinder analysis showed that RPL5 and CY were the most stable genes considering all tissues, whereas in gill HPRTI and BGLU were most stable. In gonad/digestive gland, RPL5 and TUBB were the most stable genes with geNorm, while SDHA and HPRTI were the best using NormFinder. Similarly, in head the best genes were RPL5 and UBC with geNorm, and GAPDH and CY with NormFinder. The technical variability analysis with RPL5 and abalone gonad/digestive gland tissue indicated a high repeatability with a variation coefficient within groups ≤ 0.56% and between groups ≤ 1.89%. These results will help us for further research in reproduction, thermoregulation and endocrinology in red abalone.
Assuntos
Perfilação da Expressão Gênica/normas , Genes Essenciais , Moluscos/genética , Reação em Cadeia da Polimerase em Tempo Real/normas , Animais , Feminino , Perfilação da Expressão Gênica/métodos , Gônadas/metabolismo , Masculino , Moluscos/metabolismo , Controle de Qualidade , Reação em Cadeia da Polimerase em Tempo Real/métodos , Padrões de Referência , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Estudos de Validação como AssuntoRESUMO
Metal concentrations were evaluated in water, bottom sediments, and biota in four field campaigns from 2002 to 2004 in the Potiguar Basin, northeastern Brazil, where offshore oil exploration occurs. Analyses were performed by inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry. Total metal concentrations in water (dissolved + particulate) and sediments were in the range expected for coastal and oceanic areas. Abnormally high concentrations in waters were only found for Ba (80 µg l(-1)) and Mn (12 µg l(-1)) at the releasing point of one of the outfalls, and for the other metals, concentrations in water were found in stations closer to shore, suggesting continental inputs. In bottom sediments, only Fe and Mn showed abnormal concentrations closer to the effluent releasing point. Metal spatial distribution in shelf sediments showed the influence of the silt-clay fraction distribution, with deeper stations at the edge of the continental shelf, which are much richer in silt-clay fraction showing higher concentrations than shallower sediments typically dominated by carbonates. Metal concentrations in estuarine (mollusks and crustaceans) and marine (fish) organisms showed highest concentrations in oysters (Crassostrea rhizophorae). Fish tissues metal concentrations were similar between the continental shelf influenced by the oil exploration area and a control site. The results were within the range of concentrations reported for pristine environments without metals contamination. The global results suggest small, if any, alteration in metal concentrations due to the oil exploration activity in the Potiguar Basin. For monitoring purposes, the continental inputs and the distribution of the clay-silt fraction need to be taken into consideration for interpreting environmental monitoring results.
Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/química , Metais/análise , Poluição por Petróleo , Água do Mar/química , Poluentes Químicos da Água/análise , Animais , Biota , Brasil , Crustáceos/metabolismo , Peixes/metabolismo , Metais/metabolismo , Moluscos/metabolismo , Poluentes Químicos da Água/metabolismo , Poluição Química da Água/estatística & dados numéricosRESUMO
Marine organisms represent approximately half of the world's biodiversity by virtue of the sea being an immense reservoir of bioactive molecules. Here, antimicrobial crude extract activities of different marine invertebrates from the Caribbean Sea were evaluated. One of the most active, crude extracts was that marine snail Cenchritis muricatus, it was capable of totally inhibiting the development of Staphylococcus aureus and also showed a growth inhibition of 95.9% in Escherichia coli. Aiming to isolate molecules that confirm antimicrobial activity, the crude extract was purified by reversed-phase HPLC C-18 chromatography. Thereafter, one of the obtained fractions preserved this antibacterial activity. Furthermore, SDS-PAGE analysis (15%) showed the presence of two proteins of molecular masses with approximately 10 and 15 kDa, respectively. The first 19 amino acids of both proteins were sequenced by using Edman degradation, yielding unidentified primary structures compared against sequences deposited at NCBI databank. This is the first report of antibacterial proteins isolated from the mollusk Cenchritis muricatus and these proteins could be used as antibiotic alternatives in the aquacultural industry, as well as in agricultural or biomedical research.
Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Moluscos/química , Proteínas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Região do Caribe , Avaliação Pré-Clínica de Medicamentos , Escherichia coli/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Moluscos/classificação , Moluscos/metabolismo , Proteínas/química , Proteínas/metabolismo , Staphylococcus aureus/crescimento & desenvolvimentoRESUMO
Florianópolis, a city located in the Santa Catarina State in southern Brazil, is the national leading producer of bivalve mollusks. The quality of bivalve mollusks is closely related to the sanitary conditions of surrounding waters where they are cultivated. Presently, cultivation areas receive large amounts of effluents derived mainly from treated and non-treated domestic, rural, and urban sewage. This contributes to the contamination of mollusks with trace metals, pesticides, other organic compounds, and human pathogens such as viruses, bacteria, and protozoan. The aim of this study was to perform a thorough diagnosis of the shellfish growing areas in Florianópolis, on the coast of Santa Catarina. The contamination levels of seawater, sediments, and oysters were evaluated for their microbiological, biochemical, and chemical parameters at five sea sites in Florianópolis, namely three regular oyster cultivation areas (Sites 1, 2, and oyster supplier), a polluted site (Site 3), and a heavily polluted site (Site 4). Samples were evaluated at day zero and after 14 days. Seawater and sediment samples were collected just once, at the end of the experiment. Antioxidant defenses, which may occur in contaminated environments in response to the increased production of reactive oxygen species (ROS) by organisms, were analyzed in oysters, as well as organic compounds (in oysters and sediment samples) and microbiological contamination (in oysters and seawater samples). The results showed the presence of the following contaminants: fecal coliforms in seawater samples (four sites), human adenovirus (all sites), human noroviruses GI and GII (two sites), Hepatitis A viruses (one site), JC Polyomavirus in an oyster sample from the oyster supplier, Giardia duodenalis cysts, and Cryptosporidium sp oocysts (one site). Among organochlorine pesticides, only DDT (dichlorodiphenyltrichloroethane) and HCH (hexachlorocyclohexane) were detected in some sediment and oysters samples in very low levels; site 4 had the highest concentrations of total aliphatic hydrocarbons, PAHs, and linear alkylbenzenes (LABs) found either in oysters or in sediment samples. The major concentration of fecal sterol coprostanol was found at site 4, followed by site 3. After 14 days of allocation in the four selected sites, there was a significant difference in the enzymes analyzed at the monitored spots. The detection of different contaminants in oysters, seawater, and sediment samples in the present study shows the impact untreated or inadequately treated effluents have on coastal areas. These results highlight the need for public investment in adequate wastewater treatment and adequate treatment of oysters, ensuring safe areas for shellfish production as well as healthier bivalve mollusks for consumption.
Assuntos
Monitoramento Ambiental/métodos , Moluscos/metabolismo , Poluentes Químicos da Água/análise , Poluição da Água/estatística & dados numéricos , Animais , Brasil , Substâncias Perigosas/análise , Substâncias Perigosas/metabolismo , Humanos , Invertebrados/metabolismo , Metais/análise , Metais/química , Metais/metabolismo , Norovirus/isolamento & purificação , Compostos Orgânicos/análise , Compostos Orgânicos/química , Compostos Orgânicos/metabolismo , Ostreidae/microbiologia , Ostreidae/virologia , Praguicidas/análise , Praguicidas/química , Praguicidas/metabolismo , Água do Mar/química , Água do Mar/microbiologia , Água do Mar/virologia , Esgotos/análise , Microbiologia da Água , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo , Poluição da Água/análiseRESUMO
Concentrations of organochlorine pesticides and stable isotope ratios of nitrogen and carbon were measured in a tropical freshwater ecosystem to evaluate the contamination level of biota and examine the bioaccumulation patterns of pollutants through the food web. Chemical analyses showed a general and heavy contamination of the entire food web. They revealed the strong accumulation of pollutants by juveniles of diadromous fishes and shrimps, as they re-enter the river. The role of ecological factors in the bioaccumulation of pesticides was evaluated. Whereas the most persistent pollutants (chlordecone and monohydro-chlordecone) were related to the organisms diet and habitat, bioaccumulation of ß-HCH was only influenced by animal lipid content. The biomagnification potential of chlordecone through the food chain has been demonstrated. It highlighted the importance of trophic transfer in this compound bioaccumulation process. In contrast, bioconcentration by passive diffusion from water seemed to be the main exposure route of biota to ß-HCH.
Assuntos
Organismos Aquáticos/metabolismo , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Rios/química , Poluentes Químicos da Água/análise , Animais , Biota , Clordecona/análise , Clordecona/metabolismo , Decápodes/metabolismo , Ecossistema , Monitoramento Ambiental , Peixes/metabolismo , Cadeia Alimentar , Hexaclorocicloexano/análise , Hexaclorocicloexano/metabolismo , Hidrocarbonetos Clorados/metabolismo , México , Moluscos/metabolismo , Praguicidas/metabolismo , Clima Tropical , Poluentes Químicos da Água/metabolismo , Poluição Química da Água/estatística & dados numéricosRESUMO
To assess the safety for human consumption of commercially important bivalves harvested from areas with or without mining activities, we compared the levels of heavy metals in mollusks collected from different coastal environments along the Gulf of California. We sampled the mussel Mytilus edulis and the clams Laevicardium elatum and Megapitaria squalida (June 2004) and the clam Chione californiensis (November 2006). Concentrations of cadmium, lead, nickel, zinc, iron, copper, and manganese in the soft tissue of the mollusks were measured by atomic absorption spectrophotometry. Based on dry weight, the highest average concentrations of iron, copper, and cadmium were found in clams from Loreto (572, 181, and 4.66 mg/kg, respectively); that of nickel, in mussels from San Luquitas (12.2 mg/kg); that of zinc, both in mussels from San Luquitas and in clams from Golfo de Santa Clara (94.3 and 91.8 mg/kg, respectively); and those of lead and manganese in clams from the Golfo de Santa Clara (9.2 and 3.68 mg/kg, respectively). Although mollusks were taken from coastal areas of the Gulf of California, which are considered to be contaminated by mining activities, the heavy metals in the sediments apparently were in a chemical form that had low bioavailability for the bivalves feeding in those areas. The interplay of oceanographic conditions and the chemical composition of anthropogenic inputs into the environment is not well understood. Thus, these factors or their interaction could potentially result in increased concentration and bioavailability of such metals in areas without effluent generated by mining activities.
Assuntos
Metais Pesados/metabolismo , Mineração , Moluscos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Bivalves/metabolismo , Monitoramento Ambiental , Pesqueiros , México , Mytilus/metabolismo , Oceanos e Mares , Água do MarRESUMO
Na, K, Ca, Mg, Fe, Cu, Zn, Mn, Se, Ni, and Cd concentrations were determined in 126 mollusc samples belonging to five different species (Mytilus chilensis, n = 47; Nacella deaurata, n = 65; Aulacomya ater, n = 4; Fissurella picta, n = 4; Acanthina monodon, n = 6) collected from the coasts of the Strait of Magellan. The metals analysed presented significant differences between the mean concentrations for the mollusc species considered. Factor and discriminant analyses made possible the differentiation of the mollusc species. In addition, when discriminant analysis was used, good classifications were obtained according to sampling zone and weight-to-length ratio of the organisms.
Assuntos
Monitoramento Ambiental/estatística & dados numéricos , Metais/análise , Moluscos/metabolismo , Poluentes Químicos da Água/análise , Animais , Chile , Análise Discriminante , Análise Fatorial , Metais/metabolismo , Poluentes Químicos da Água/metabolismoRESUMO
In early April 2003, fishermen from Kino Bay Sonora alerted us about a massive die-off of fish and mollusks occurring at Kun Kaak Bay. Phytoplankton samples taken on 17 May 2003 reported the presence of a harmful algal bloom composed of Chatonella marina, Chatonella cf. ovata, Gymnodinium catenatum and Gymnodinium sanguineum. On 22 of May, we collected samples of water, sediment and organisms at the affected area. Physicochemical parameters and nutrients were measured in water samples from different depths. Sediment and benthic organisms were analyzed for Cd, Cu, Zn, Pb and Hg. We found concentrations of heavy metals higher than background levels for this area. Cadmium and Lead concentrations in sediment from the HAB area were up to 6x greater than background levels and Cd in mollusks was 8x greater than regulations allow. A relationship between elevated Cd and Pb concentrations in sediment and the survival of toxic dinoflagellates is suspected.
Assuntos
Eucariotos , Sedimentos Geológicos/química , Metais Pesados/análise , Moluscos/química , Poluentes Químicos da Água/análise , Animais , Monitoramento Ambiental , Metais Pesados/toxicidade , México , Moluscos/metabolismo , Oceanos e Mares , Poluentes Químicos da Água/toxicidadeRESUMO
The distal pocket of hemoglobin II (HbII) from Lucina pectinata is characterized by the presence of a GlnE7 and a TyrB10. To elucidate the functional properties of HbII, biophysical studies were conducted on HbII and a HbI PheB10Tyr site-directed mutant. The pH titration data at neutral conditions showed visible bands at 486, 541, 577 and 605 nm for both proteins. This suggests the possible existence of a conformational equilibrium between an open and closed configuration due to the interactions of the TyrB10, ligand, and heme iron. The kinetic behavior for the reaction of both ferric proteins with H2O2 indicates that the rate for the formation of the ferryl intermediates species varies with pH, suggesting that the reaction is strongly dependent on the conformational states. At basic pH values, the barrier for the reaction increases as the tyrosine adopts a closed conformation and the ferric hydroxyl replaces the met-aquo species. The existence of these conformers is further supported by resonance Raman (RR) data, which indicate that in a neutral environment, the ferric HbII species is present as a possible mixture of coordination and spin states, with values at 1558 and 1580 cm(-1) for the nu2 marker, and 1479, 1492, and 1503 cm(-1) for the nu3 mode. Moreover, the presence of the A3 and A(o) conformers at 1924 and 1964 cm(-1) in the HbII-CO infrared spectra confirms the existence of an open and closed conformation due to the orientation of the TyrB10 with respect to the heme active center.
Assuntos
Heme/química , Hemoglobinas/química , Moluscos/metabolismo , Tirosina/química , Animais , Heme/metabolismo , Hemoglobinas/genética , Peróxido de Hidrogênio/farmacologia , Concentração de Íons de Hidrogênio , Ferro/química , Cinética , Ligantes , Modelos Químicos , Mutação , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Tirosina/metabolismoAssuntos
Amônia/metabolismo , Cádmio/toxicidade , Moluscos/efeitos dos fármacos , Nitrogênio/metabolismo , Oxigênio/metabolismo , Respiração/efeitos dos fármacos , Zinco/toxicidade , Amônia/urina , Animais , Moluscos/metabolismo , Moluscos/fisiologia , Testes de Toxicidade , Poluentes da Água/toxicidadeRESUMO
Os escargots são animais capazes de produzir através de glândulas localizadas em toda superfície do seu corpo, uma secreção glicoproteica com um poder antibacteriano que participa na própria imunidade inata¹. O poder antimicrobiano de determinadas substâncias pode auxiliar nos processos de reparação de feridas de origens diversas. Desta forma, o objetivo do presente trabalho foi o de avaliar macroscopicamente e histologicamente, os efeitos reparadores do muco do escargot Achatina fulica, em lesões provocadas por instrumento cortante na pele de coelhos. Incisões de 10cm de comprimento foram realizadas na pele de 15 coelhos. Estes foram divididos em três grupos e submetidos aos respectivos tratamentos: 1) tratamento com o muco na forma pura, 2) tratamento com o muco sob a forma de pomada e 3) um grupo sem receber o tratamento (controle). As características macroscópicas da lesão foram registradas diariamente e para a análise histológica, uma biópsia foi realizada após 72 horas de tratamento. Os fragmentos processados rotineiramente e corados com Tricrômio de Masson. Histologicamente, a epiderme dos coelhos tratados mostrou uma camada basal de células cúbicas, enquanto os do grupo controle apresentaram uma camada basal de células cilíndricas com áreas desorganizadas e a derme apresentou um estágio mais avançado no processo de reparo quando comparado ao controle. A evolução macroscópica no processo de cicatrização ocorreu num menor espaço de tempo nos coelhos do grupo pomada, em relação aos demais tratamentos.
Escargots are animals capable to produce a glycoproteic secretion by glands located in all the surface of their bodies which among other functions presents anti-bacterial power and participation in the own immunity. The antimicrobioan power of certain substances may aid of repair of wounds with several origins. Thus, the aim of the present study was to evaluate macroscopic and histologically the reparative effects of the mucus of Achatina fulica escargots on lesions made in the skin of rabbits. Incisions were performed in the skin of 15 rabbits, separated in three groups according to the treatment received. Immediately after the lesion, the respective treatments with pure mucus form and in ointment form were supplied, while the other group received no treatment (control group). The macroscopic characteristics of the lesion were registered daily and a biopsy was performed 72 hours after the treatments. The fragments were processed and stained with Masson's trichrome. The macroscopic evolution in the cicatrization process ocurred in a shorter period of time in rabbits from the ointment group, comparativity with the other groups. Histologically, the epidermis of the treated rabbits showed a basal layer of cubic cells, while rabbits of the control group presented a basal layer of cylindrical cells with cutaneous debris.