Freshwaters Dotaz Zobrazit nápovědu
The Asian fish tapeworm (AFT), Schyzocotyle acheilognathi, is a notorious and highly successful invasive parasite reported in a wide spectrum of freshwater fishes, and new reports of its spread continue to emerge. To date, no thorough review of its worldwide distribution and host associations is available. In the present work, we collected information from 651 articles up until 2017, from which we updated the number of the hosts to 312 fish species and 11 non-fish species, which is quite unusual among helminths. The AFT has spread to all but one continent (Antarctica). The highest number of records are from North America, followed by Asia and Europe. A key feature of its invasive success is its broad environmental tolerance.
- MeSH
- Cestoda klasifikace fyziologie MeSH
- cestodózy parazitologie MeSH
- hostitelská specificita fyziologie MeSH
- nemoci ryb parazitologie MeSH
- rozšíření zvířat * MeSH
- ryby MeSH
- sladká voda MeSH
- zavlečené druhy * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Geografické názvy
- Asie MeSH
- Evropa MeSH
- Severní Amerika MeSH
Successful co-introduction of a parasite and its host relies not only on presence of the parasite on host individuals in the founder population but also on the ability of both host and parasite to persist in the new area. Gyrodactylus proterorhini (Monogenea) has been successfully co-introduced with its Ponto-Caspian goby hosts (Babka gymnotrachelus, Neogobius fluviatilis, Neogobius melanostomus, Ponticola kessleri, Proterorhinus semilunaris) to many freshwater systems in Europe and is now widely distributed over four large European river basins (Danube, Rhine, Scheldt and Vistula). Within Europe, higher infection levels are documented in sites further from the native host range. In North America, however, G. proterorhini appears to be absent. Host specificity of G. proterorhini tested under natural conditions showed accidental host-switching onto local fish species (native Perca fluviatilis and non-native Perccottus glenii) in the river Vistula. Further examination of host-switching under experimental conditions, however, showed that G. proterorhini were unable to survive on non-gobiid hosts longer than 24 h. Our results indicate extremely low potential for host-switching of introduced G. proterorhini to non-gobiid hosts, at least in the freshwater systems of Central and Western Europe.
- MeSH
- hostitelská specificita fyziologie MeSH
- infekce červy třídy Trematoda epidemiologie parazitologie veterinární MeSH
- Perciformes parazitologie MeSH
- řeky parazitologie MeSH
- Trematoda izolace a purifikace MeSH
- zeměpis MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa epidemiologie MeSH
- Severní Amerika epidemiologie MeSH
A survey was carried out on occurrence of Mycobacterium marinum in fish kept in aquaria and those living in their natural environment. Species-specific qPCR targeting the erp and IS2404 genes together with the conventional culture method were used. The analysis of 72 ornamental fish (n = 216 samples: gills, muscle and intestine) collected from aquaria revealed the presence of M. marinum in 30 individuals (41.7%) of whom 17 (23.6%) were later culture positive. Culture-independent detection revealed the presence of M. marinum in 16 of 83 environmental samples (19.3%) collected in aquaria. The presence of viable M. marinum cells was later confirmed in 5 samples (6.0%). No qPCR or culture positivity was observed when 123 groundwater fish and their corresponding environmental samples (n = 142) were analysed.
- MeSH
- atypické mykobakteriální infekce epidemiologie mikrobiologie veterinární MeSH
- bakteriální proteiny genetika MeSH
- kosterní svaly mikrobiologie MeSH
- molekulární sekvence - údaje MeSH
- multiplexová polymerázová řetězová reakce veterinární MeSH
- Mycobacterium marinum genetika izolace a purifikace MeSH
- nemoci ryb epidemiologie mikrobiologie MeSH
- počet mikrobiálních kolonií veterinární MeSH
- prevalence MeSH
- RNA ribozomální 16S genetika MeSH
- ryby MeSH
- sekvenční analýza DNA veterinární MeSH
- sladká voda mikrobiologie MeSH
- střeva mikrobiologie MeSH
- žábry mikrobiologie MeSH
- zvířata v ZOO mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- Evropa MeSH
Neotropical freshwater stingrays (Batoidea: Potamotrygonidae) host a diversity of parasites, including some, like their hosts, that are marine-derived. Among the parasites of potamotrygonids, the cestode fauna is the most diverse, with multiple genera having been reported, including genera endemic to the freshwaters of the Neotropics and genera that have cosmopolitan distributions. Recent efforts have been made to document the diversity of cestodes of this host-parasite system and to refine the taxonomy of parasite lineages. The present study contributes to our knowledge of Rhinebothrium Linton, 1890, a diverse cosmopolitan genus of rhinebothriidean cestode, with 37 species reported from marine batoids, one species from a freshwater stingray in Borneo and six species from potamotrygonids. Rhinebothrium jaimei sp. n. is described from two species of potamotrygonids, Potamotrygon orbignyi (Castelnau) (type host) and Potamotrygon scobina Garman, from Bahía de Marajó of the lower Amazon region. It can be distinguished from most of its marine congeners via multiple attributes, including its possession of two, rather than one, posteriormost loculi on its bothridia and the lomeniform shape of its bothridium that is wider anteriorly. In addition, R. jaimei sp. n. can be distinguished from the six Rhinebothrium species described previously from potamotrygonids based on a unique combination of morphological features. Despite extensive stingray cestode sampling efforts throughout all major Neotropical river systems, we found that unlike most species of potamotrygonid Rhinebothrium species, which are widespread, R. jaimei sp. n. is restricted to the Bahía de Marajó. The discovery of this new species of Rhinebothrium in Bahía de Marajó, an area in which potamotrygonids occur sympatrically with some species of euryhaline batoids (e.g. Dasyatis spp.) and share some trophic resources, suggest that modern ecological processes may be contributing to the distribution patterns of cestodes infecting potamotrygonids.
Low-GC Actinobacteria are among the most abundant and widespread microbes in freshwaters and have largely resisted all cultivation efforts. Consequently, their phages have remained totally unknown. In this work, we have used deep metagenomic sequencing to assemble eight complete genomes of the first tailed phages that infect freshwater Actinobacteria. Their genomes encode the actinobacterial-specific transcription factor whiB, frequently found in mycobacteriophages and also in phages infecting marine pelagic Actinobacteria. Its presence suggests a common and widespread strategy of modulation of host transcriptional machinery upon infection via this transcriptional switch. We present evidence that some whiB-carrying phages infect the acI lineage of Actinobacteria. At least one of them encodes the ADP-ribosylating component of the widespread bacterial AB toxins family (for example, clostridial toxin). We posit that the presence of this toxin reflects a 'trojan horse' strategy, providing protection at the population level to the abundant host microbes against eukaryotic predators.
- MeSH
- Actinobacteria klasifikace genetika virologie MeSH
- bakteriofágy klasifikace genetika izolace a purifikace MeSH
- fylogeneze MeSH
- genom virový MeSH
- metagenomika MeSH
- sladká voda mikrobiologie virologie MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A survey of the occurrence of mycobacteria was conducted from 717 freshwater fish (25 species) in two water reservoirs, five ponds and two farms in the Czech Republic. A total of 2182 tissue samples from these fish were examined using the conventional culture method. Thirteen mycobacterial isolates were obtained from 12 (1.7%) fish belonging to nine species. Isolates were identified using sequence analysis of the 16SrRNA gene as: Mycobacterium algericum, M. fortuitum, M. gordonae, M. insubricum, M. kumamotonense, M. nonchromogenicum, two isolates of M. peregrinum, M. terrae and M. triplex. Mycobacteria were isolated more frequently from fish skin and gills than from internal organs or muscles.
- MeSH
- Mycobacterium genetika izolace a purifikace MeSH
- mykobakteriózy epidemiologie veterinární MeSH
- nemoci ryb epidemiologie mikrobiologie MeSH
- prevalence MeSH
- RNA ribozomální 16S genetika MeSH
- rybníky MeSH
- ryby MeSH
- sladká voda MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Two new species of Rhinebothrium (Cestoda, Rhinebothriidea) from potamotrygonid stingrays in the Neotropical region are herein described, which raises the total number of Rhinebothrium species known from Neotropical freshwaters to five. Rhinebothrium corbatai sp. n., and Rhinebothrium mistyae sp. n. were both collected from Potamotrygon motoro (Müller et Henle), captured in four tributaries of the Paraná River in Santa Fé Province, Argentina. The new species can be distinguished from their congeners, and from each other, by a combination of various features, including worm size (length and number of proglottids), number of loculi per bothridium, microthrix pattern, size of the cirrus sac, and the extent of the vas deferens. The discovery of these new species from P. motoro supports the pattern of high host specificity in this cestode genus, and reinforces the notion that some of the previous records of the enigmatic R. paratrygoni may correspond to new species of Rhinebothrium yet to be described.
Small bacterivorous eukaryotes play a cardinal role in aquatic food webs and their taxonomic classification is currently a hot topic in aquatic microbial ecology. Despite increasing interest in their diversity, core questions regarding predator-prey specificity remain largely unanswered, e.g., which heterotrophic nanoflagellates (HNFs) are the main bacterivores in freshwaters and which prokaryotes support the growth of small HNFs. To answer these questions, we fed natural communities of HNFs from Římov reservoir (Czech Republic) with five different bacterial strains of the ubiquitous betaproteobacterial genera Polynucleobacter and Limnohabitans. We combined amplicon sequencing and catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH) targeting eukaryotic 18 S rRNA genes to track specific responses of the natural HNF community to prey amendments. While amplicon sequencing provided valuable qualitative data and a basis for designing specific probes, the number of reads was insufficient to accurately quantify certain eukaryotic groups. We also applied a double-hybridization technique that allows simultaneous phylogenetic identification of both predator and prey. Our results show that community composition of HNFs is strongly dependent upon prey type. Surprisingly, Cryptophyta were the most abundant bacterivores, although this phylum has been so far assumed to be mainly autotrophic. Moreover, the growth of a small lineage of Cryptophyta (CRY1 clade) was strongly stimulated by one Limnohabitans strain in our experiment. Thus, our study is the first report that colorless Cryptophyta are major bacterivores in summer plankton samples and can play a key role in the carbon transfer from prokaryotes to higher trophic levels.
- MeSH
- Bacteria klasifikace genetika izolace a purifikace metabolismus MeSH
- Cryptophyta mikrobiologie MeSH
- fylogeneze MeSH
- heterotrofní procesy MeSH
- hybridizace in situ fluorescenční MeSH
- plankton mikrobiologie MeSH
- potravní řetězec MeSH
- roční období MeSH
- sladká voda mikrobiologie parazitologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Stream ecosystems face ever-increasing pressures by the presence of emergent contaminants, such as, personal care products. N, N-diethyl-3-methylbenzamide (DEET) is a synthetic insect repellent that is being found in surface waters environments in concentrations up to 33.4 μg/L. Information concerning DEET's toxicity in the aquatic environment is still limited and focused only on its acute effects on model species. Our main objective was to assess the effects of DEET exposure to a caddisfly non-target species using sub-lethal endpoints. For that, we chose Sericostoma vittatum, an important shredder in Portuguese freshwaters that has been already used in different ecotoxicological assays. Besides acute tests, S. vittatum were exposed during 6 days to a gradient of DEET concentrations (8, 18 and 40.5 mg/L) to assess effects on feeding behaviour and biochemical responses, such as, lipid peroxidation levels (LPO), catalase and acetylcholinesterase (AChE) activities, and also assess effects on energy reserves and consumption. Acute tests revealed a 48 h-LC50 of 80.12 mg/L and DEET exposure caused feeding inhibition with a LOEC of 36.80 mg/L. Concerning the biochemical responses, DEET caused no effects in LPO nor on catalase activity. A non-significant decrease in AChE activity was observed. Regarding energetic reserves, exposure to DEET caused a significant reduction in S. vittatum carbohydrates levels. These results add important information for the risk assessment of insect repellents in the aquatic environment and suggest that reported environmental concentrations of DEET are not toxic to non-target freshwater insects.
- MeSH
- chemické látky znečišťující vodu toxicita MeSH
- diethyltoluamid toxicita MeSH
- hmyz účinky léků fyziologie MeSH
- insekticidy toxicita MeSH
- katalasa MeSH
- repelenty proti hmyzu toxicita MeSH
- sladká voda MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
