Review on the molecular study of the Diplozoidae: analyses of currently available genetic data, what it tells us, and where to go from here (original) (raw)
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Everything is New: Host, Parasite and Insight Into Taxonomic Division of Diplozoidae
Monogeneans belonging to the Diplozoidae are common parasites on the gills of cyprinid fish but host specificity of diplozoids differs and relates to the geographical origin of the host. The size and shape of sclerotized parts of attachment apparatus of adults (four pairs of clamps and a pair of small central hooks) are commonly used for the species identification of diplozoids. The length of the central hook sickle and the shape of the anterior end of median plate and anterior joining sclerites of the clamps were confirmed to be the most significant features for species discrimination. In Turkey, only four diplozoid species have been recorded up to date mostly on cyprinid hosts genera. In our study, we used morphological approach in combination with recent molecular analyses and made a new parasite species description (Paradiplozoon bingolensis sp. n.) in new cyprinid host species (Garra rufa, Heckel 1843). Samples of fish were collected from the Göynük Stream, a tributary of the M...
Checklists of Diplozoid Species (Monogenea) from Fishes of Iraq
Surveying 59 references concerning the occurrence of the monogeneans of the family Diplozoidae parasitizing fishes of Iraq showed the occurrence of 15 valid species of this family which included one species of Diplozoon, one species of Eudiplozoon and 13 species of Paradiplozoon. In addition to these species, some unidentified adult and larval (diporpa larvae) specimens of the genus Diplozoon were reported from 12 fish hosts among which four fish species showed no infection with any of the nominated diplozoid species while the others showed mixed diplozoid infections. These diplozoids were reported from 27 fish host species in Iraq. All the diplozoids were recorded from freshwater habitats except one Dipolzoon sp. which was recorded from a marine habitat. Hosts recorded for each of these diplozoids ranged from a minimum of one host in case of both P. ergensi and P. tadzhikistanicum to a maximum of 13 hosts in case of P. kasimii. Among the infected fishes, 13 hosts harbored only one ...
Turkish Journal of Fisheries and Aquatic Sciences
Diplostomid trematodes (Digenea) include a wide and diverse group of common digeneans. Diplostomid larval stages are significant pathogens that may exert grave effects on both natural fish and aquaculture populations. Diplostomum species, which use fish as a second intermediate host, is one of the most common trematode species, which affects the fish welfare negatively with the formation of cataracts by settling in the eye. This study is determined the molecular characterization of Diplostomum parasite in Cyprinus carpio and Capoeta umbla for the first time from Turkey, based on the mitochondrial COX1 sequence data. Diplostomum samples were determined as Diplostomum spathaceum according to the phylogenetic trees created in the light of the morphological and COX1 sequence data. Sequence results matched ~98-100% with D. spathaceum as a result of blast analysis. It was defined that this parasite was represented by three different haplotypes in Turkey. As a result of haplotype analysis ...
Parasitology Research, 2013
The paper presents a description of Paradiplozoon bingolensis sp. n. from the gills of Garra rufa Heckel, 1843 (Cyprinidae) collected from the Göynük Stream, a tributary of the Murat River, Turkey. This is the first diplozoid species to be described from G. rufa. P. bingolensis is distinguished from the other valid species in the genus by the combination of the morphology of the sclerites of its clamps and by the size of the central hooks. Even molecular characterization based on variability of the second internal transcribed spacer (ITS2) of the ribosomal DNA region provided additional support of separation of this new species from the valid ones. The sequences were compared with previously published ITS2 sequences of other diplozoid species. Subsequent analysis demonstrated the uniqueness of this new parasite species and revealed uncertainties in the current taxonomic division of the Diplozoidae that are commented in the text.
International Journal for Parasitology, 2008
Parasite species with global distributions and complex life cycles offer a rare opportunity to study alternative mechanisms of speciation and evolution in a single model. Here, genealogy and genetic structure, with respect to geography and fish host preference, have been analyzed for Ligula intestinalis, a tapeworm affecting freshwater fish. The data analyzed consisted of 109 tapeworms sampled from 13 fish host species in 18 different localities on a macrogeographic scale. Two mitochondrial genes, cytochrome oxidase subunit I and cytochrome B, and the nuclear sequence of intergenic transcribed spacer 2 (ITS2) were used for the genetic reconstruction. Different evolutionary patterns were found at the local and at the global geographic scales. On a local scale, the flat genetic structure was mainly attributed to contiguous range expansion. Migrating birds are the most likely cause of the homogenisation of the whole population, preventing the creation of significant genetic barriers. By contrast, on a global scale, genetically distant and well-separated clusters are present in different geographic areas. Reproductive isolation was found even between clades living in sympatry and infecting the same definitive host, suggesting the existence of efficient biologically determined genetic barriers, and thus possibly separate species. Although the ITS2 sequences were found to display considerable intragenomic variability, their relationships were generally in good agreement with the topology derived from mitochondrial genes. Ó
International Journal for Parasitology: Parasites and Wildlife
Reliable data on the diversity of the genus Diplostomum (Digenea: Diplostomidae) parasitising freshwater fishes in South Africa, as well as in Africa, is almost non-existent. Most of the morphology-based identifications of species within this genus reported from Africa require critical revision. The aim of the present study was to determine the diversity of Diplostomum metacercariae in South African fishes applying molecular and traditional morphological techniques. To achieve this aim, a total of 216 fishes belonging to 21 species collected in the Rivers Phongolo, Riet, Usuthu and Mooi in three provinces of South Africa were examined. Metacercariae of Diplostomum were recovered from the eye lenses of 38 fishes belonging to five species of the families Anguillidae, Cichilidae and Mochokidae, with an overall low prevalence of infection (18%). Metacercariae were subjected to morphological study and molecular sequencing of the partial mithochondrial cox1 and ribosomal 28S rDNA genes as well as of ribosomal ITS1-5.8S-ITS2 region. Morphological and phylogenetic analyses revealed the presence of three species which matched those previously reported from Nigeria, Iraq and China, therefore those from Tilapia sparrmanii and Synodontis zambezensis were named Diplostomum sp.; those from Anguilla labiata, Oreochromis mossambicus and S. zambezensis were named Diplostomum sp. 14; and those from Pseudocrenilabrus philander were named Diplostomum sp. 16. Geographic distribution of several species of Diplostomum appeared to be wider than expected. Morphological description and novel sequence data generated during this study will contribute to the elucidation of the life cycles of Diplostomum sp., Diplostomum sp. 14 and Diplostomum sp. 16 and advance further research of diplostomids in Africa.
Parasites & vectors, 2017
Metacercariae of Diplostomum are important fish pathogens, but reliable data on their diversity in natural fish populations are virtually lacking. This study was conducted to explore the species diversity and host-parasite association patterns of Diplostomum spp. in a large riverine system in Europe, using molecular and morphological data. Twenty-eight species of fish of nine families were sampled in the River Danube at Nyergesújfalu in Hungary in 2012 and Štúrovo in Slovakia in 2015. Isolates of Diplostomum spp. were characterised morphologically and molecularly. Partial sequences of the 'barcode' region of the cytochrome c oxidase subunit 1 (cox1) and complete sequences of the nicotinamide adenine dinucleotide dehydrogenase subunit 3 (nad3) mitochondrial genes were amplified for 76 and 30 isolates, respectively. The partial cox1 sequences were used for molecular identification of the isolates and an assessment of haplotype diversity and possible host-associated structuring...
Acta Aquatica Turcica, 2020
This study was aimed to identify Paradiplozoon bliccae (Monogenea: Diplozoidae) in an endemic fish species Pseudophoxinus burduricus (Teleostei: Cyprinidae) and to describe parasite’s prevalence and intensity of infection. P. burduricus specimens were collected between January 2014 and February 2015 in Doğanbaba Creek (Yeşilova-Burdur). A total of 60 P. burduricus specimens were examined for monogenean parasites. During the course of surveys, diplozoid specimens were collected from the gills of these fish and examined microscopically for identification. Paradiplozoon bliccae specimens were isolated from the examined fish. Prevalence, intensity, and seasonality of infection, age classes, and sex compositions of the infected population have been calculated. It has been recorded that the highest point of prevalence being in summer and the highest invasion value in the two-age class of fish. Hyperaemia, haemorrhage, and atrophy of the gills were observed during pathological examination ...
International Journal for Parasitology, 2015
Larvae (metacercariae) in some species of Diplostomidae (Platyhelminthes: Digenea) inhabit fish eyes and are difficult to identify to species based on morphology. DNA barcoding has clarified the diversity and life cycles of diplostomids in North America, Europe and Africa, but has seldom been used in parasites sampled in large numbers or at large spatial scales. Here, distance-based analysis of cytochrome c oxidase 1 barcodes and, in some specimens, internal transcribed spacer (ITS-1, 5.8S, ITS-2) sequences was performed for over 2000 diplostomids from Africa, the Middle East, Europe, Asia and the Americas. Fifty-two species of Diplostomum, Tylodelphys and Austrodiplostomum (Digenea: Diplostomidae) were distinguished. The 52 species comprise 12 identified species, six species in two species complexes and 34 putative species, and 33/52 had been delineated in previous studies. Most (23/40) of the unidentified, putative species distinguished by cytochrome c oxidase 1 distances were supported by at least one additional line of evidence. As the intensity of sampling of the 52 species increased, variation in cytochrome c oxidase 1 decreased between and increased within species, while the spatial scale at which species were sampled had no effect. Nonetheless, variation between species always exceeded variation within species. New life-cycle linkages, geographic and host records, and genetic data were recorded in several species, including Tylodelphys jenynsiae, Tylodelphys immer and Diplostomum ardeae. Species of Diplostomum inhabiting the lens are less host-specific and less numerous than those infecting other tissues, suggesting that reduced immune activity in the lens has influenced rates of speciation. Ó Please cite this article in press as: Locke, S.A., et al. Diversity, specificity and speciation in larval Diplostomidae (Platyhelminthes: Digenea) in the eyes of freshwater fish, as revealed by DNA barcodes. Int. J. Parasitol. (2015), http://dx.
Genetics of Aquatic Organisms, 2021
In this study, identification of the cytochrome c oxidase subunit I (COI) gene region in mitochondrial DNA of the Diplostomum specimens, which are parasitic in the eyes of Capoeta umbla fish naturally distributed in Karakaya Dam Lake, Keban Dam Lake and Lake Hazar, (Elazığ province) was performed. A total of 8 haplotypes were determined using sequence analysis of the mtCOI gene region and phylogenetic trees were constructed by determining the genetic distance based on these haplotypes by the Maximum Likelihood (ML), Neighbor Joining (NJ), Minimum Evolution (ME) and Bayes methods. As a result, the lowest genetic distance was 0,00209 and the highest genetic distance was 0,01264. Phylogenetic analysis revealed a closer relationship between haplotype 3 and haplotype 4. It has been evaluated that all the samples studied belong to Diplostomum spathaceum and that the parasite may have been spread by the main hosts between study sites.