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1.
Eur J Protistol ; 71: 125634, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31585231

RESUMO

Vannella samoroda n. sp. (Amoebozoa, Vannellida) was isolated from the mouth of the Malaya Samoroda river flowing into Elton, the largest European hypersaline lake (Russia). Among all rivers of the area, it has the highest salt content (ca. 110‰). Amoebae maintained in seawater medium with ca. 77‰ salts concentration had a set of morphological characters typical of Vannella spp.: rounded, fan-shaped, or spatulate locomotive form, floating form with bent, blunt-ended hyaline pseudopodia, and a cell coat consisting of regularly packed palisade elements and scarce simple filaments. Phylogenetic analyses based on SSU rRNA and cytochrome C oxidase subunit 1 genes show that the amoeba is most closely related to Vannella ebro Smirnov, 2001, but represents a distinct species. The clade of V. ebro and V. samoroda branches among marine species of Vannella. The studied species is the first member of the genus Vannella from a continental saline habitat described using molecular data. Interestingly, it has a broad range of salinity tolerance: cells reproduce above 18‰, while survival of a few cells regularly occurs even in highly diluted Prescott and James medium. The normal culture restores itself when PJ medium is substituted with 77‰ seawater medium even after months of experimental incubation.


Assuntos
Amebozoários/classificação , Filogenia , Água do Mar/parasitologia , Amebozoários/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , RNA Ribossômico 18S/genética , Federação Russa , Especificidade da Espécie
2.
Parasit Vectors ; 12(1): 472, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31604479

RESUMO

BACKGROUND: The parasitic dinoflagellates of the genus Hematodinium represent the causative agent of so-called bitter or pink crab disease in a broad range of shellfish taxa. Outbreaks of Hematodinium-associated disease can devastate local fishing and aquaculture efforts. The goal of our study was to examine the potential role of the common shore (green) crab Carcinus maenas as a reservoir for Hematodinium. Carcinus maenas is native to all shores of the UK and Ireland and the North East Atlantic but has been introduced to, and subsequently invaded waters of, the USA, South Africa and Australia. This species is notable for its capacity to harbour a range of micro- and macro-parasites, and therefore may act as a vector for disease transfer. METHODS: Over a 12-month period, we interrogated 1191 crabs across two distinct locations (intertidal pier, semi-closed dock) in Swansea Bay (Wales, UK) for the presence and severity of Hematodinium in the haemolymph, gills, hepatopancreas and surrounding waters (eDNA) using PCR-based methods, haemolymph preparations and histopathology. RESULTS: Overall, 13.6% were Hematodinium-positive via PCR and confirmed via tissue examination. Only a small difference was observed between locations with 14.4% and 12.8% infected crabs in the Dock and Pier, respectively. Binomial logistic regression models revealed seasonality (P < 0.002) and sex (P < 0.001) to be significant factors in Hematodinium detection with peak infection recorded in spring (March to May). Male crabs overall were more likely to be infected. Phylogenetic analyses of the partial ITS and 18S rRNA gene regions of Hematodinium amplified from crabs determined the causative agent to be the host generalist Hematodinium sp., which blights several valuable crustaceans in the UK alone, including edible crabs (Cancer pagurus) and langoustines (Nephrops norvegicus). CONCLUSIONS: Shore crabs were infected with the host generalist parasite Hematodinium sp. in each location tested, thereby enabling the parasite to persist in an environment shared with commercially important shellfish.


Assuntos
Alveolados/patogenicidade , Braquiúros/parasitologia , Reservatórios de Doenças/parasitologia , Alveolados/classificação , Alveolados/genética , Alveolados/fisiologia , Animais , Distribuição Binomial , DNA Espaçador Ribossômico/genética , Dinoflagelados/classificação , Dinoflagelados/genética , Dinoflagelados/patogenicidade , Dinoflagelados/fisiologia , Feminino , Brânquias/parasitologia , Hemolinfa/química , Hemolinfa/parasitologia , Modelos Logísticos , Masculino , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 18S/análise , Estações do Ano , Água do Mar/parasitologia , País de Gales
3.
Eur J Protistol ; 71: 125633, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31520849

RESUMO

Loricate choanoflagellate genera that incorporate flattened costal strips in the lorica (i.e. Calotheca, Stephanacantha, Thomsenella (= Platypleura) and Syndetophyllum) are prevalent in warm water habitats. The genus Thomsenella (=Platypleura) thus comprises four species and three of these have an Andaman Sea type locality. Our ongoing examination of loricate choanoflagellate material from all major warm water oceans has provided us with the opportunity of revisiting species of Thomsenella in order to test and fortunately verify, in a morpho-specific context, the robustness of the species matrix initially defined.


Assuntos
Coanoflagelados/classificação , Temperatura Alta , Água do Mar/parasitologia , Coanoflagelados/citologia , Coanoflagelados/fisiologia , Ecossistema , Especificidade da Espécie
4.
Eur J Protistol ; 71: 125632, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31563814

RESUMO

Aided by an extensive collection of specimens from warm water seas, it has been possible to revisit the loricate choanoflagellate genus Cosmoeca. While the type species C. norvegica and also C. ventricosa sensu stricto have been described from temperate North Atlantic realms and share a cosmopolitan distribution, the remaining species and morphotypes of Cosmoeca are largely confined to warmer waters. The new data broadly validates the initial circumscription of species of Cosmoeca. The persisting taxonomic puzzle with respect to C. ventricosa, which in addition to the core type accommodates no less than five different morphotypes (form A-E), has been further elucidated. The Cosmoeca paper is part of a 'monographic' series of warm water loricate choanoflagellate contributions in progress, where the aim is to provide the best possible account of warm water species diversity, based on traditional light and electron microscopical techniques, as a tool for future identification work based on microscopy, and in support of the work in progress with establishing a quality assured molecular tool for future recognition of diversity.


Assuntos
Biodiversidade , Coanoflagelados/classificação , Temperatura Alta , Coanoflagelados/citologia , Coanoflagelados/ultraestrutura , Água do Mar/parasitologia , Especificidade da Espécie
5.
Eur J Protistol ; 71: 125635, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31553939

RESUMO

The morphology, infraciliature, and silverline system of two peritrich ciliates, Pseudovorticella littoralis sp. n. and P. alani sp. n., isolated from coastal waters of southern China, were investigated based on both living and silver-stained specimens. Pseudovorticella littoralis sp. n. is characterized by the following combination of characters: cell inverted cone-shaped; contractile vacuole ventral; J-shaped macronucleus; infundibular polykinety 3 with two kinetosome rows of equal length; 19-26 silverlines from peristome to trochal band and 5-14 from trochal band to scopula. Pseudovorticella alani sp. n. is characterized by: cell inverted bell-shaped; contractile vacuole ventral; J-shaped macronucleus recurved almost forming a loop; infundibular polykinety 3 with three kinetosome rows, outer two rows longer than inner one; 48-61 silverlines between peristome and aboral trochal band, and 12-20 between aboral trochal band and scopula. The SSU rDNA sequences of both new species are reported and their genetic distances with congeners and phylogenetic relationships are investigated. Pseudovorticella and Epicarchesium cluster into two subclades with low support values. One subclade contains nearly all the available sequences of Pseudovorticella and Epicarchesium. Another one contains P. monilata and E. pectinatum. This calls on the need of a generic re-classification of Pseudovorticella and Epicarchesium based on more morphological and molecular data.


Assuntos
Oligoimenóforos/classificação , Filogenia , Água do Mar/parasitologia , China , Oligoimenóforos/citologia , Oligoimenóforos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
6.
Eur J Protistol ; 70: 1-16, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31176174

RESUMO

Although it is widely recognized that oligotrich ciliates are the dominant constituent of microzooplankton communities and perform key functions in energy flow and material cycling in marine microbial food webs, knowledge of their diversity is scant. In the present study, we investigate the oligotrich genera, Cyrtostrombidium and Apostrombidium, with emphasis on their morphology and evolutionary relationships. Three isolates were collected from coastal waters of northern and southern China including two new species, viz., Cyrtostrombidium paraboreale sp. n., Apostrombidium orientale sp. n., and Apostrombidium pseudokielum Xu et al., 2009. Cyrtostrombidium paraboreale sp. n. is characterized by possessing 64-98 cytopharyngeal rods and two macronuclear nodules. Apostrombidium orientale sp. n. is characterized by its somatic kinety consisting of five fragments including a horizontally orientated subterminal fragment and possessing conspicuously long dorsal cilia. Apostrombidium pseudokielum is redescribed based on the new population and a re-examination of the type material. Phylogenetic analyses were performed for the subclass Oligotrichia, incorporating SSU rRNA gene sequences of the three species investigated here. The results indicate that the genus Cyrtostrombidium is monophyletic with C. paraboreale sp. n. occupying the basal position. The genus Apostrombidium is not monophyletic as Varistrombidium kielum is nested within it.


Assuntos
Organismos Aquáticos/classificação , Cilióforos/classificação , Filogenia , Organismos Aquáticos/citologia , Organismos Aquáticos/genética , China , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/genética , DNA Ribossômico/genética , Água do Mar/parasitologia , Especificidade da Espécie
7.
Eur J Protistol ; 69: 102-116, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31035014

RESUMO

New phagotrophic euglenoid species from marine surface waters and the deep sea were isolated and described by light and scanning electron microscopy and 18S rDNA sequencing: Keelungia nitschei, Petalomonas acorensis and Ploeotia costaversata. The morphological characteristics of Keelungia nitschei agree with Keelungia pulex besides the slightly truncated anterior front of the cell of our strain. Phylogenetic analysis indicated low sequence similarity between K. nitschei and K. pulex (87.3%). Ploeotia costaversata clustered within the Ploeotia costata clade with a sequence similarity of 96.1% to P. costata strain Tam. Ultrastructural characteristics of our strain revealed helically twisted strips towards both poles of the protoplast. 18S rDNA phylogenies showed that Petalomonas acorensis is related to the clade of Petalomonas cantuscygni/Scytomonas saepesedens with the highest sequence similarity of 81.2% to P. cantuscygni. Six pellicle strips are visible, while two of them reach only the middle of the cell and four (two longitudinal, two helically twisted) join at the posterior front of the cell. Pressure experiments showed that the deep-sea strain K. nitschei was better adapted to high hydrostatic pressures (up to 500 bar) at 4 °C than the two surface water strains. All three strains increased the database (18S rDNA) of the underrepresented group of phagotrophic euglenids.


Assuntos
Euglênidos/classificação , Água do Mar/parasitologia , Oceano Atlântico , Euglênidos/citologia , Euglênidos/genética , Filogenia , RNA Ribossômico 18S/genética , Especificidade da Espécie
8.
Parasitol Res ; 118(5): 1647-1651, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30904928

RESUMO

A new coelozoic myxozoan species, Ceratomyxa batam n. sp., was identified in cultured carangid fish, Trachinotus ovatus (Perciformes: Carangidae), in waters off Batam Island of Indonesia. The bi- and trivalved spores were observed in the gallbladder of T. ovatus. Mature bivalved spores of C. batam n. sp. were transversely elongated and narrowly crescent in shape, 3.8 ± 0.36 (2.7-4.6) µm long and 19.2 ± 1.75 (16.2-22.0) µm thick. Two sub-spherical polar capsules were 2.3 ± 0.18 (2.0-2.8) µm long and 2.6 ± 0.16 (2.3-2.9) µm wide. Prevalence was 72.2% in 72 examined T. ovatus according to evaluations dating from November 2016. The maximum likelihood phylogenetic tree based on small subunit rDNA sequence showed similarity with Ceratomyxa robertsthomsoni and Ceratomyxa thalassomae found in Australia. This is the first report of Ceratomyxa species identified in a seawater fish at Batam Island, Indonesia.


Assuntos
Doenças dos Peixes/parasitologia , Vesícula Biliar/parasitologia , Myxozoa/classificação , Doenças Parasitárias em Animais/parasitologia , Perciformes/parasitologia , Esporos/classificação , Animais , DNA Ribossômico/genética , Peixes/parasitologia , Indonésia , Myxozoa/genética , Filogenia , Água do Mar/parasitologia , Esporos/genética , Esporos/isolamento & purificação
9.
Eur J Protistol ; 67: 114-131, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30616105

RESUMO

The main outcome of this and subsequent papers is to provide a baseline survey of heterotrophic protist diversity from warm water marine ecosystems, exemplified by loricate choanoflagellates (Acanthoecida). Genera in focus here (i.e. Bicosta, Apheloecion, Campyloacantha, Crucispina, Calliacantha and Saroeca) possess anterior spines or projections and a posterior pedicel, and have 0, 1 or 2 transverse costae. Longitudinal costae are, with the exception of Campyloacantha, external to transverse costal elements across all genera examined here. We describe here Apheloecion eqpacia sp. nov. and Calliacantha magna sp. nov., both of which are so far distributionally confined to warm water habitats. A 'form A' of Bicosta minor is introduced to facilitate the distinction between B. minor sensu stricto and a presumed warm water adapted variant with a posterior lorica chamber twist of the longitudinal costae.


Assuntos
Biodiversidade , Coanoflagelados/classificação , Coanoflagelados/citologia , Água do Mar/parasitologia , Adaptação Fisiológica , Animais , Especificidade da Espécie , Temperatura Ambiente
10.
FEMS Microbiol Lett ; 366(2)2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30629176

RESUMO

Diatom diazotroph associations (DDAs) are a widespread marine planktonic symbiosis between several diatom genera and di-nitrogen (N2)-fixing bacteria. Combining single cell confocal microscopy observations and molecular genetic approaches on individual field collected cells, we determined the phylogenetic diversity, distribution and evolution of the DDAs. Confocal analyses coupled with 3-D imaging re-evaluated the cellular location of DDA symbionts. DDA diversity was resolved by paired gene sequencing (18S rRNA and rbcL genes, 16S rRNA and nifH genes). A survey using the newly acquired sequences against public databases found sequences with high similarity (99-100%) to either host (18S rRNA) or symbiont (16S rRNA) in atypical regions for DDAs (high latitudes, anoxic basin and copepod gut). Concatenated phylogenies were congruent for the host and cyanobacteria sequences and implied co-evolution. Time-calibrated trees dated the appearance of N2 fixing planktonic symbiosis from 100-50Mya and were consistent with the symbiont cellular location: symbioses with internal partners are more ancient. An ancestral state reconstruction traced the evolution of traits in DDAs and highlight that the adaptive radiation to the marine environment was likely facilitated by the symbiosis. Our results present the evolutionary nature of DDAs and provide new genetic and phenotypic information for these biogeochemically relevant populations.


Assuntos
Evolução Biológica , Cianobactérias/genética , Diatomáceas/genética , Variação Genética , Simbiose , Cianobactérias/classificação , Cianobactérias/isolamento & purificação , Cianobactérias/fisiologia , Diatomáceas/classificação , Diatomáceas/microbiologia , Diatomáceas/fisiologia , Fixação de Nitrogênio , Filogenia , Água do Mar/microbiologia , Água do Mar/parasitologia
11.
Microb Ecol ; 78(2): 388-408, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30623212

RESUMO

One of the most prominent manifestations of climate change is the changing Arctic sea-ice regime with a reduction in the summer sea-ice extent and a shift from thicker, perennial multiyear ice towards thinner, first-year ice. These changes in the physical environment are likely to impact microbial communities, a key component of Arctic marine food webs and biogeochemical cycles. During the Norwegian young sea ICE expedition (N-ICE2015) north of Svalbard, seawater samples were collected at the surface (5 m), subsurface (20 or 50 m), and mesopelagic (250 m) depths on 9 March, 27 April, and 16 June 2015. In addition, several physical and biogeochemical data were recorded to contextualize the collected microbial communities. Through the massively parallel sequencing of the small subunit ribosomal RNA amplicon and metagenomic data, this work allows studying the Arctic's microbial community structure during the late winter to early summer transition. Results showed that, at compositional level, Alpha- (30.7%) and Gammaproteobacteria (28.6%) are the most frequent taxa across the prokaryotic N-ICE2015 collection, and also the most phylogenetically diverse. Winter to early summer trends were quite evident since there was a high relative abundance of thaumarchaeotes in the under-ice water column in late winter while this group was nearly absent during early summer. Moreover, the emergence of Flavobacteria and the SAR92 clade in early summer might be associated with the degradation of a spring bloom of Phaeocystis. High relative abundance of hydrocarbonoclastic bacteria, particularly Alcanivorax (54.3%) and Marinobacter (6.3%), was also found. Richness showed different patterns along the depth gradient for prokaryotic (highest at mesopelagic depth) and protistan communities (higher at subsurface depths). The microbial N-ICE2015 collection analyzed in the present study provides comprehensive new knowledge about the pelagic microbiota below drifting Arctic sea-ice. The higher microbial diversity found in late winter/early spring communities reinforces the need to continue with further studies to properly characterize the winter microbial communities under the pack-ice.


Assuntos
Bactérias/isolamento & purificação , Biodiversidade , Eucariotos/isolamento & purificação , Camada de Gelo/microbiologia , Camada de Gelo/parasitologia , Regiões Árticas , Bactérias/classificação , Bactérias/genética , Eucariotos/classificação , Eucariotos/genética , Camada de Gelo/química , Filogenia , Estações do Ano , Água do Mar/química , Água do Mar/microbiologia , Água do Mar/parasitologia , Svalbard
12.
Nursing ; 49(1): 40-43, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30586048

RESUMO

Nurses may see patients who have recently returned from tropical vacations complaining of a severe pruritic dermatitis known as seabather's eruption (SBE). Caused by exposure to jellyfish larvae, SBE is characterized by a pruritic rash, but some patients, particularly children, experience systemic signs and symptoms such as fever, chills, and nausea/vomiting. This article discusses SBE and reviews assessment tips, nursing care, and patient teaching.


Assuntos
Copépodes , Dermatite/etiologia , Dermatite/enfermagem , Temperatura Alta/efeitos adversos , Água do Mar/parasitologia , Natação , Animais , Humanos , Avaliação em Enfermagem , Educação de Pacientes como Assunto
13.
Environ Sci Pollut Res Int ; 26(3): 2592-2602, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30474813

RESUMO

To evaluate the water quality status using ecological features of the periphytic ciliate communities, a 1-year (Jan. to Dec., 2016) investigation was conducted in coastal waters of the Yellow Sea, northern China. Four trophic-functional groups (TFgrs) were recorded from a total of 141 species-abundance dataset: algivores (A); bacterivores (B); non-selectives (N); and predators (R), comprising of 65, 34, 26, and 16 species, respectively. In terms of species number, TFgr A was predominant in clean areas while TFgrs B and N were dominant in heavy polluted areas and TFgr R was dominant in slightly polluted area. The trophic-functional patterns of the periphytic ciliate communities showed a clear spatial variation within the pollution gradient. Trophic-functional trait diversity measures represented a clear increasing trend from polluted stations to the clean area regarding the pollution gradients. Multivariate correlation and best matching analysis revealed that the spatial pattern of the trophic-functional groupings were significantly shaped by environmental variable nutrients and chemical oxygen demand, alone or in combination with pH, dissolved oxygen, salinity, and transparency. Thus, we suggest that the ecological features based on the trophic-functional patterns of periphytic ciliate communities might be used for bioassessment of water quality in marine ecosystems.


Assuntos
Cilióforos/crescimento & desenvolvimento , Água do Mar/química , Biodiversidade , Análise da Demanda Biológica de Oxigênio , China , Cilióforos/metabolismo , Ecologia , Ecossistema , Monitoramento Ambiental , Oxigênio/metabolismo , Salinidade , Água do Mar/parasitologia , Qualidade da Água
14.
Microb Ecol ; 78(1): 1-5, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30448922

RESUMO

In the marine environment, the abundance of Bacteria and Archaea is either controlled bottom-up via nutrient availability or top-down via grazing. Heterotrophic nanoflagellates (HNF) are mainly responsible for prokaryotic grazing losses besides viral lysis. However, the grazing specificity of HNF on specific bacterial and archaeal taxa is under debate. Bacteria and Archaea might have different nutritive values and surface properties affecting the growth rates of HNF. In this study, we offered different bacterial and archaeal strains with different morphologic and physiologic characteristics to Cafeteria roenbergensis, one of the most abundant and ubiquitous species of HNF in the ocean. Two Nitrosopumilus maritimus-related strains isolated from the northern Adriatic Sea (Nitrosopumilus adriaticus, Nitrosopumilus piranensis), two Nitrosococcus strains, and two fast growing marine Bacteria (Pseudoalteromonas sp. and Marinobacter sp.) were fed to Cafeteria cultures. Cafeteria roenbergensis exhibited high growth rates when feeding on Pseudoalteromonas sp., Marinobacter sp., and Nitrosopumilus adriaticus, while the addition of the other strains resulted in minimal growth. Taken together, our data suggest that the differences in growth of Cafeteria roenbergensis associated to grazing on different thaumarchaeal and bacterial strains are likely due to the subtle metabolic, cell size, and physiological differences between different bacterial and thaumarchaeal taxa. Moreover, Nitrosopumilus adriaticus experienced a similar grazing pressure by Cafeteria roenbergensis as compared to the other strains, suggesting that other HNF may also prey on Archaea which might have important consequences on the global biogeochemical cycles.


Assuntos
Archaea/isolamento & purificação , Bactérias/isolamento & purificação , Estramenópilas/fisiologia , Archaea/classificação , Archaea/genética , Bactérias/classificação , Bactérias/genética , Comportamento Alimentar , Cadeia Alimentar , Processos Heterotróficos , Água do Mar/microbiologia , Água do Mar/parasitologia , Estramenópilas/classificação , Estramenópilas/crescimento & desenvolvimento
15.
Microb Ecol ; 77(2): 394-405, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30083828

RESUMO

The heterotrophic labyrinthulomycete protists have long been known to play an important role in the nutrient cycling of coastal seawater. Yet, their spatiotemporal abundance and diversity in polluted coastal waters remain poorly discussed, due in part to the paucity of a rapid detection method. To this end, we developed a qPCR detection method based on a newly designed primer pair targeting their 18S rRNA gene. Using this method, we studied the population dynamics of labyrinthulomycete protists in nutrient-rich (Shenzhen Bay) and low-nutrient (Daya) coastal habitats along the Pearl River Delta. We found a significantly (P < 0.05) higher abundance of Labyrinthulomycetes in the Shenzhen bay (average 3455 gene copies mL-1) than that in Daya Bay (average 378 gene copies mL-1). Their abundance gradient positively correlated (P < 0.05) with the levels of inorganic nitrogen and phosphates. Further characterization of the molecular diversity of these protists in Shenzhen Bay using different primer sets revealed the presence of several genera besides a large number of unclassified OTUs. Regardless of the primer biases, our results show significant (P < 0.05) spatiotemporal changes in the molecular abundance and diversity of these heterotrophic protists. Overall, this study provides a rapid molecular detection tool for Labyrinthulomycetes and expands our current understanding of their dynamics controlled by physicochemical gradients in coastal waters.


Assuntos
Biodiversidade , Rios/parasitologia , Água do Mar/parasitologia , Estramenópilas/isolamento & purificação , Nitrogênio/análise , Nitrogênio/metabolismo , Fosfatos/análise , Fosfatos/metabolismo , Filogenia , RNA Ribossômico 18S/genética , Rios/química , Água do Mar/química , Estramenópilas/classificação , Estramenópilas/genética , Estramenópilas/metabolismo
16.
Eur J Protistol ; 67: 77-88, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30522008

RESUMO

The main outcome of this and subsequent papers is to provide a baseline survey of heterotrophic protist diversity from warm water marine ecosystems, exemplified by loricate choanoflagellates (Acanthoecida). Loricate choanoflagellates are heterotrophic, nano-sized protists that are ubiquitous in marine and brackish water habitats. They dwell in a lorica formed by silicified costal strips organized in species specific patterns. The single anteriorly directed flagellum is surrounded by a collar formed by microvilli which together constitute the feeding apparatus. Keystone benefits from this warm water survey, which covers all three major oceans, is an improved understanding of global biogeographical patterns, and a further consolidation of the morphospecies matrix, that constitutes a highly essential reference framework for the current efforts to provide barcodes for as many species of loricate choanoflagellates as possible, based on e.g. single cell pipetting techniques. We describe here Conioeca gen. et sp. nov., which is so far distributionally confined to warm water habitats, and elaborate on the morphological variability encountered within the N. minuta complex. This leads to both the circumscription of a new N. minuta form A as well as the description of N. mexicana sp. nov.


Assuntos
Organismos Aquáticos/classificação , Organismos Aquáticos/citologia , Coanoflagelados/classificação , Coanoflagelados/citologia , Distribuição Animal , Água do Mar/parasitologia , Especificidade da Espécie , Temperatura Ambiente
17.
Parasit Vectors ; 11(1): 633, 2018 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-30545426

RESUMO

BACKGROUND: Functional inference on the attachment of acanthocephalans has generally been drawn directly from morphology. However, performance of structures is often non-intuitive and context-dependent, thus performance analysis should be included whenever possible to improve functional interpretation. In acanthocephalans, performance analysis of attachment is available only for Acanthocephalus ranae, a species that solely relies on the proboscis to attach. Here we compare body morphology and muscle arrangement in 13 species of Corynosoma, which use their spiny body as a fundamental holdfast. A basic performance analysis using live cystacanths of two representative species is also provided. METHODS: Adults of 13 Corynosoma spp. were obtained from 11 marine mammal species. Specimens were cut and carefully cleaned to examine muscle arrangement through light and scanning electron microscopy. Live cystacanths of C. australe and C. cetaceum were selected for performance analysis. Video records of evagination-invagination cycles of the proboscis were obtained and analysed with a video editor. RESULTS: The basic arrangement of proboscis retractors, trunk circular and longitudinal muscles, neck retractors and receptacle retractors, was conserved in all Corynosoma species. Interspecific variability was found in the relative development of disk muscles: minimum in C. enhydri, maximum in C. cetaceum; the distal insertion of the ventral neck retractor: ventro-lateral in C. cetaceum, C. hamannni and C. pseudohamanni and ventral in the other species; and the distal insertion of the receptacle retractors: more proximal in species with a longer hindtrunk. Performance analysis indicated striking similarities to that described for A. ranae except that (i) the foretrunk bends ventrally during the evagination-invagination cycles of the proboscis; (ii) disk muscles can flatten the tip of the foretrunk regardless of these cycles; and (iii) the receptacle bends ventrally and is driven to the hindtrunk by coordinated action of receptacle retractors. CONCLUSIONS: Species of Corynosoma are able to use up to six holfast mechanisms. Attachment relies on a similar performance to that described for A. ranae. However, structural ventral bending of an inflated, spiny foretrunk, with a parallel re-arrangement of foretrunk muscles, have generated unexpected novel functions that make attachment extremely effective in species of Corynosoma. Interspecific variability in trunk shape and muscle arrangement grossly correlates with the rheological conditions each species experiences in their microhabitats within the gut of marine mammals.


Assuntos
Acantocéfalos/anatomia & histologia , Acantocéfalos/fisiologia , Acantocéfalos/ultraestrutura , Animais , Feminino , Helmintíase Animal/parasitologia , Interações Hospedeiro-Parasita/fisiologia , Masculino , Mamíferos/parasitologia , Microscopia Eletrônica de Varredura , Músculos/anatomia & histologia , Músculos/fisiologia , Músculos/ultraestrutura , Água do Mar/parasitologia , Gravação em Vídeo
18.
Parasit Vectors ; 11(1): 609, 2018 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-30497499

RESUMO

BACKGROUND: The causal relation between parasitic sea lice on fish farms and sea lice on wild fish is a controversial subject. A specific scientific debate has been whether the statistical association between infestation pressure (IP) from fish farms and the number of parasites observed on wild sea trout emerges purely because of a confounding and direct effect of temperature (T). METHODS: We studied the associations between louse infestation on wild sea trout, fish farm activity and temperature in an area that practices coordinated fallowing in Nordhordland, Norway. The data were sampled between 2009 and 2016. We used negative binomial models and mediation analysis to determine to what degree the effect of T is mediated through the IP from fish farms. RESULTS: The number of attached lice on sea trout increased with the T when the IP from fish farms was high but not when the IP was low. In addition, nearly all of the effect of rising T was indirect and mediated through the IP. Attached lice remained low when neighbouring farms were in the first year of the production cycle but rose substantially during the second year. In contrast to attached lice, mobile lice were generally seen in higher numbers at lower water temperatures. Temperature had an indirect positive effect on mobile louse counts by increasing the IP which, in turn, raised the sea trout louse counts. Mobile louse counts rose steadily during the year when neighbouring farms were in the first year of the production cycle and stayed high throughout the second year. CONCLUSIONS: The estimates of the IP effect on louse counts along with the clear biennial pattern emerging due to the production cycle of fish farms clearly indicate that fish farms play an important role in the epidemiology of sea lice on wild sea trout. Furthermore, the mediation analysis demonstrates that a large proportion of the effect of T on louse counts is mediated through IP.


Assuntos
Arguloida/fisiologia , Doenças dos Peixes/parasitologia , Infestações por Piolhos/veterinária , Truta/parasitologia , Animais , Animais Selvagens/parasitologia , Aquicultura , Arguloida/genética , Infestações por Piolhos/parasitologia , Modelos Estatísticos , Noruega , Água do Mar/química , Água do Mar/parasitologia , Temperatura Ambiente
19.
PLoS One ; 13(12): e0208158, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30586401

RESUMO

Benthic foraminifera, and certainly symbiont-bearing (large) benthic foraminifera are generally considered to have large geographic ranges in combination with significant ecomorphological variation. With the advance of molecular phylogenetic approaches, supported or preceded by detailed morphological studies, it was demonstrated that this view needs to be reevaluated. In this paper I evaluate the morphology of five Marginopora populations from around the Coral Sea by microCT-scanning. I argue that ecomorphological and ontogenetic variation is smaller than geographic variation in morphology. This forms the basis for the description of three new species, M. santoensis nov. spec., M. charlottensis nov. spec., M. orpheusensis nov. spec. Quantitative morphological variation between M. rossi, M. orpheusensis nov. spec. and M. charlottensis nov. spec. is overlapping, but each species has unique morphological characters supporting recognition as new species. Support to distinguish the deep living (M. rossi, M. charlottensis nov. spec., M. orpheusensis nov. spec.) and shallow living (M. vertebralis) Marginopora populations as separate species is strong, but not enough molecular phylogenetic data are available to test the three new deep-living species on the Great Barrier Reef hypothesis. However, detailed understanding of ecophenotypic variation in M. santoensis nov. spec. supports the conclusion that it is unlikely that ecophenotypic variation can explain the morphological variation between the three species. I argue that the number of species in this genus is underestimated, and that there are at least five species in the Coral Sea area alone.


Assuntos
Variação Anatômica , Biodiversidade , Foraminíferos/ultraestrutura , Água do Mar/parasitologia , Recifes de Corais , Oceano Pacífico , Microtomografia por Raio-X
20.
Sci Rep ; 8(1): 14020, 2018 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-30232358

RESUMO

The ecology and distribution of green phytoplankton (Chlorophyta) in the ocean is poorly known because most studies have focused on groups with large cell size such as diatoms or dinoflagellates that are easily recognized by traditional techniques such as microscopy. The Ocean Sampling Day (OSD) project sampled surface waters quasi-simultaneously at 141 marine locations, mostly in coastal waters. The analysis of the 18S V4 region OSD metabarcoding dataset reveals that Chlorophyta are ubiquitous and can be locally dominant in coastal waters. Chlorophyta represented 29% of the global photosynthetic reads (Dinoflagellates excluded) and their contribution was especially high at oligotrophic stations (up to 94%) and along the European Atlantic coast. Mamiellophyceae dominated most coastal stations. At some coastal stations, they were replaced by Chlorodendrophyceae, Ulvophyceae, Trebouxiophyceae or Chlorophyceae as the dominating group, while oligotrophic stations were dominated either by Chloropicophyceae or the uncultured prasinophytes clade IX. Several Chlorophyta classes showed preferences in terms of nitrate concentration, distance to the coast, temperature and salinity. For example, Chlorophyceae preferred cold and low salinity coastal waters, and prasinophytes clade IX warm, high salinity, oligotrophic oceanic waters.


Assuntos
Clorófitas/classificação , Água do Mar/parasitologia , Clorófitas/genética , Bases de Dados Factuais , Microalgas/classificação , Microalgas/genética , Filogenia , RNA Ribossômico 18S/genética , Análise de Sequência de DNA/métodos
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