EDP Sciences logo
Submit your paper
Search
Menu
All issues Volume 25 (2018) Parasite, 25 (2018) 4 Full HTML
Open Access
Issue
Parasite
Volume 25, 2018
Article Number 4
Number of page(s) 8
DOI https://doi.org/10.1051/parasite/2018004
Published online 09 February 2018

© D. Jirsová et al., published by EDP Sciences, 2018

Licence Creative CommonsThis is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Introduction

Members of the class Monogenoidea (parasites of salt and freshwater fish) can be classified into two subclasses: Polyonchoinea and Heteronchoinea [4]. Within the Heteronchoinea (infrasubclass Oligonchoinea), the Diplozoidae Tripathi, 1959 represents a specific monogenean group parasitising the gills of freshwater fishes. Diplozoids are obligatory blood-feeding ectoparasites with an unusual life cycle wherein two immature individuals (diporpa) meet on the gills of a fish and subsequently permanently fuse together into an X-shaped adult ’individual’ [18,35]. Each adult worm (i.e. each ’side’ of a fused individual) has a forebody and an ovarium and testis in each hindbody. The adult has two attachment apparatuses, each having four pairs of clamps and a pair of small central hooks situated on the ventral side of the respective opisthaptors.

According to Khotenovsky (1985) [18], the Diplozoidae is represented by two subfamilies: Diplozoinae Palombi, 1949 (five genera) and Neodiplozoinae Khotenovsky, 1980 (two genera). Morphological features (e.g. size of body, size of clamps) vary widely within diplozoid species, depending on size of the host fish and the developmental stage of the diplozoon [23,24], making determination to species level difficult. In general, the central hooks and clamp sclerites are considered the structures of most taxonomic relevance [5,11,18,22]. In more recent years, genetic analysis of molecular markers has been used to counter morphological similarities when differentiating species [21–23,34]. It is widely assumed that the majority of diplozoids are highly specific to their hosts; indeed, most follow their specific fish host throughout their distribution range and they are very likely to have co-evolved together [17,38]. As such, host-species determination has often been used for general identification of the parasite [16]. One exception to this general ’rule’ is the generalist parasite Paradiplozoon homoion (Bychowsky & Nagibina, 1959), which has been recorded from more than fifteen cyprinid fish species [10,18,21].

In China, 33 species have been reported from five diplozoine genera, 23 from Paradiplozoon, six from Sindiplozoon, two from Inustiatus, one from Diplozoon, and one from Eudiplozoon [3,9,36,39]. Several authors [9,39] have published information on Chinese diplozoid species, including the original description of Paradiplozoon hemiculteri by Ling (1973); however, the morphological descriptions in these studies have largely been imperfect and/or inaccurate e.g. Chen (1973) [6] or the studies were based on molecular data only [9]. Despite all the published work concerning Chinese diplozoons, the molecular data are not accurate and none of the published studies adequately combined and reviewed morphological and molecular data [22,7,1,31–33]. Moreover, according to the curator of the collection, Mr. Weijian Yao, and specialists from the Institute of Hydrobiology, Chinese Academy of Sciences, where the type material of P. hemiculteri should be located, the types of this species are missing and likely lost. Therefore, we collected new material from Shaoguan, Guangdong Province neotype locality and type host, from which a neotype for P. hemiculteri was selected and designated. In this work, we redescribe P. hemiculteri based on the new morphological and molecular data from the neotype and new specimens from the type host in southern China.

Material and Methods

Sampling

As the type specimens of P. hemiculteri are now unavailable, the present study is based on morphological and molecular examination of ten adult diplozoid worms collected from the gills of Hemiculter leucisculus (Basilewsky, 1855), the type host fish species, from the neotype locality in Shaoguan, Guangdong Province, southern China (24.810329°N 113.597547°E) in 2015. Two individuals already fused into the X-shaped adult worm were separated, one haptor being fixed in 96% ethanol for molecular investigation. The second haptor was placed on a slide in a drop of water, covered with the cover slide, while excess water was drawn off with filtration paper until rupture of the parasite’s body appeared, and the sample was infiltrated/fixed with ammonium picrate-glycerine 1:1 (GAP) [8,20] for morphometric analysis.

Morphological analysis

After the fixation of the haptor in GAP, the sclerites of diplozoid clamps laid nearly in one plane, enabling accurate measurement.

An Olympus BX51 light microscope (Olympus, Japan) equipped with differential interference contrast and Stream Motion digital image analysis software v. 1.5 was used to measure the length and width of the body, buccal suckers, pharynx, attachment clamps and the central hook sickle and handle [18]. All measurements were performed 8-16 times. An Olympus U-DA drawing attachment was used to create outline drawings of the central hook clamps and sickle. The haptoral terminology used herein follows Pečínková et al. (2007) [26].

Molecular analysis

The DNA from ten samples was isolated according to the protocol published by Zavodna et al., (2008) [40]. Sequencing of the second rDNA internal transcribed spacer (ITS2) was used for molecular identification, using PCR primers adopted from Bachellerie & Qu (1993) [2]. The PCR reaction (50 μl) for amplification of the ITS2 region consisted of 5 μl 2x High Fidelity PCR Buffer (Thermo Scientific), 5 μl 25 mM MgCl2, 2 μl 10 mM dNTP, 1 μl (5 U/μl) of Taq DNA polymerase (Thermo Scientific), 32 μl PCR H2O, 2 μl 10 μM specific forward primer (DITS2F 5́-GGCTYRYGGNGTCGATGAAGAACGCAG-3́) and reverse primer (DITS2R 5́-GCCGGATCCGAATCCTGGTTAGTTTC TTTTCCT-3́), and 1 μl (50 ng) of DNA template. Amplification took place in a MyCycler thermal cycler system (Bio-Rad, USA) using the following protocol: 94 °C for 2 min; 30 times 94 °C for 30 s, 58 °C for 30 s, 72 °C for 60 s and a final 10 min extension at 72 °C. The PCR products obtained were separated on agarose gel (1%), stained with GoldView (Dongsheng Biotech), purified using a High Pure PCR Product Purification Kit (Roche) and cloned onto Escherichia coli TOP10 using the CloneJET PCR Cloning Kit (Thermo Scientific), according to the manufacturer’s protocol. Colonies were subsequently checked for fragment presence using PCR, with positive plasmids isolated using the High Pure Plasmid Isolation Kit (Roche) and sequenced in both directions using DITS2F and DITS2R PCR primers. The individual sequences obtained were compared with the NCBI database using the Basic Local Alignment Search Tool (BLAST).

Phylogenetic analysis

All sequences were aligned and manually edited using Geneious software v 6.1.8 [17]. The final dataset consisted of our data and all available Paradiplozoon spp. sequences from GenBank (Table 1), the whole dataset being aligned using the MAFFT software package [15]. The most suitable nucleotide substitution model was chosen according to Akaike Information Criteria using jModeltest software v 2.1.4 [27]. Phylogenetic analysis was performed on the model with the best likelihood score (GTR + G) on MrBayes v 3.2.2 Bayesian inference software [13,30], using 20 million Markov chain Monte Carlo generations with four chains and four independent runs. Convergence of runs was checked using AWTY software (Are We There Yet [25]) in order to estimate burn-in. Maximum-likelihood phylogeny was performed under the same model using PHYML software v 3.0 [12]. The reliability of branching patterns within trees was tested by the bootstrap method with 1,000 re-samplings. The final trees were visualised in FigTree software v 1.4.2 [28]. The sequence of closely related Inustiatus inustiatus (DQ098893) was used as the outgroup for both phylogenetic analyses (see Table 1).

Table 1

GenBank ITS2 sequences of monogenean species selected for phylogenetic analysis. Paradiplozoon hemiculteri GenBank sequences are marked with an asterisk; data obtained for this study are also underlined. Outgroup sequence of Inustiatus inustiatus is in bold.

Paradiplozoon hemiculteri (Ling, 1973)

Type host: Hemiculter leucisculus (Basilewsky, 1855)

Site: Gills

Original type locality: Huanggang, Hubei Province, People’s Republic of China (30.44°N, 114.87°E).

Original type material: The holotype originally described by Ling, 1973 is now unavailable (catalogue number unavailable).

Neotype locality: Shaoguan, Guangdong Province, People’s Republic of China (24.810329°N, 113.597547°E).

Type material: Type specimens apparently lost. Official collection where the types of P. hemiculteri should be located: Laboratory of Fish Parasitology, Institute of Hydrobiology, Chinese Academy of Sciences, People’s Republic of China.

Neotype material: The IPCAS M-565 P. hemiculteri neotype and three voucher specimens are deposited at the Institute of Parasitology, Czech Academy of Sciences, České Budějovice, Czech Republic. Three further voucher specimens are deposited at the Laboratory of Fish Parasitology, School of Life Science, South China Normal University, People’s Republic of China.

Article 75 of International Commission on Zoological Nomenclature was thoroughly followed.

Redescription (Figs. 1a,b; 2a,b) 

Adult Diplozoidae (Diplozoinae with Paradiplozoon characteristics [18]) display a typical X-shaped body, divided into a fore- and hindbody (Fig. 1a).

Total body length, including haptor, 3153 μm (range 2320-4180, n = 8); maximum body width 931 μm (729-1140, n = 8). Oral opening sub-terminal, pair of oval-shaped buccal suckers of 58 (50-67) x 54 (42-65) μm (n = 16), located ventrally at the anterior part of the body, near to the opening of a muscular pharynx; pharynx 66 (50-83) x 54 (38-62) μm (n = 16). Branched intestinal caeca located in the forebody, though some branches reach the hindbody near the attachment apparatus. Intestinal caeca run in all directions. Vitellaria present in the forebody; ovarium and testis located in the hindbody along with a clearly visible ootype. Eggs were not observed.

The opisthaptors in the adult worm each comprise four pairs of clamps organised into two rows with two central hooks between them (Fig. 1b, 2a). The first (anterior-most) and smallest clamp is 56 μm (42-70) long and 90 μm (72-119) wide (n = 16), the second 60 μm (49-69) x 104 μm (91-115) (n = 16), the third 61 μm (47-82) x 107 μm (74-127) (n = 16), and the fourth 62 μm (47-82) x 105 μm (76-126) (n = 16).

The clamps are formed by fine sclerites. The anterior end of the median plate is rectangular with rounded corners and a narrow trapeze spur connected to the anterior end of the plate. The anterior joining sclerite, connected to the proximal tip of the anterior jaw, has the typical inverted V-shape. The posterior end of the median plate narrows and terminates with a wide rounded sclerite with an opening. The posterior joining sclerite is the same length as the anterior joining sclerite.

The central hooks are situated near the first (anterior-most) pair of clamps. The length of the central hook sickle was 17.6 μm (17.0-18.1) (n = 16) and handle length was 36.6 μm (34-37.9) (n = 16). A barely visible wing covers the blade. Complete drawings of the third clamp and central hook of the neotype are provided in Figs. 2a, 2b.

thumbnail Figure 1

Paradiplozoon hemiculteri. A) Overall total; B) Detail of the two rows of clamps on the opisthaptor.
thumbnail Figure 2

Paradiplozoon hemiculteri clamp. A) Clamp morphology (scale bar = 50 μm); a) anterior end of median plate, b) trapeze spur, c) anterior joining sclerite, d) proximal tip of anterior jaw, e) posterior end of median with a wide rounded sclerite, f) posterior joining sclerite, g) medial sclerite of posterior jaw, i) lateral sclerite of posterior jaw. B) Central hook sickle (scale bar = 20 μm).

Molecular analysis

DNA sequences isolated and amplified from the ITS2 fragment (762 bp) of ten adult worms were all similar, with less than 1% variability. The ten sequences have now been deposited in GenBank under accession numbers KY124645 − KY124654.

Phylogenetic analysis

As the results of Bayesian inference and maximum likelihood analysis were almost identical, we pooled the results into one figure. The final tree is based on Bayesian inference phylogenetic tree topology with branch supports stated for both analysis types (bootstrap and posterior probability; Fig. 3).

All our samples clustered together and created a well-supported and separated group from those of P. hemiculteri sequences deposited in GenBank. Genetic distances between our sequences ranged between 0.1 and 0.3% (Fig. 3). Interestingly, all P. hemiculteri sequences deposited in GenBank (DQ098884 [host: Hemiculter leucisculus], DQ098886 [host: H. leucisculus], DQ098887 [host: H. leucisculus], DQ098892 [host: H. leucisculus], KY290757-61 [host: H. leucisculus]) clustered with different Paradiplozoon species (P. diplophyllorchidis, P. opsariichthydis, P. parabramisi, P. jiangxiensis and P. parapeleci), respectively.

thumbnail Figure 3

Concatenated phylogenetic tree based on ITS2 sequences for selected diplozoids. Constructed using MrBayes software, the tree includes results for Bayesian inference and maximum-likelihood with PP/bootstrap branch support. Genetic distance between our sequence data is listed below the branch support. Sequences of Paradiplozoon hemiculteri previously stored in GenBank are marked with an asterisk. Data obtained for this study are highlighted by grey gradient.

Discussion

In reviewing the available literature and corresponding sequence data deposited in public databases, we observed that taxonomic classification of the Asian diplozoon P. hemiculteri, a parasite of the gills of H. leucisculus, remains somewhat controversial at this time. Morphological descriptions of diplozoons isolated from H. leucisculus tend to be either inaccurate or inconsistent, with published illustrations of the clamps and central hook often ignoring key characteristic markers [9,18,39]. Furthermore, some of the sequences available in GenBank (i.e. DQ098884, DQ098887, DQ098888, DQ098892, KY290757-61) are probably misnamed as P. hemiculteri. In order to address this, we performed parallel morphological and molecular analyses on ten samples collected from the gills of the original type host H. leucisculus caught at the neotype locality, Shaoguan, Guangdong Province, southern China.

Based on our re-evaluation of the major morphological features (length and width of the body, buccal suckers, pharynx, attachment clamps, sickle and central hook handle), we determined that our specimens represent P. hemiculteri naturally parasitising the type host H. leucisculus. We evaluated our redescription based on published results of other authors [6,18,39]. While previous drawings of the main morphological characteristics (e.g. the two rows of clamps) were neither consistent nor always accurate, we were able to compare them to our own results and thereby distinguish our samples from other diplozoons. Unfortunately, the relevant type material of P. hemiculteri is now unavailable, hence further morphological comparison was impossible.

Due to the inconsistencies in previously published morphological data on P. hemiculteri, we decided to undertake additional molecular analysis based on amplification of the 762 bp ITS2 fragment from DNA templates of ten adult worms (see above). Our sequence data did not match any sequence saved in GenBank, including some sequences already assigned as P. hemiculteri (GenBank accession numbers DQ098884, DQ098886, DQ098887, DQ098892, KY290757-61 [9]). The genetic distance between ITS2 sequences in our dataset was almost negligible, ranging from 0.1-0.3% (Fig. 3), supporting the assumption that all sequences are related to the same diplozoid species. Recently, Gao (2007) [9] also performed a study on diplozoons originating from H. leucisculus; however, they used molecular methods and sequence data only, without supplementary morphological analysis. The absence of such morphological parameters could have led to incorrect assignment to species. Furthermore, phylogenetic analysis of the majority of P. hemiculteri nucleotide sequences available in public databases (before our own input; marked with an asterisk in Table 1, Fig. 3) indicates that all sequences clustered into one clade together with other species. Moreover, according to the phylogenetic analyses, we might assume that Paradiplozoon is paraphyletic as was also shown in the work of Gao (2007) [9]. However, these results would need revision because the relevant evaluation of potential paraphyly in the Paradiplozoon group cannot be based on the single Sindiplozoon ctenopharyngodoni sequence included in the analysis.

Based on the high morphological similarity and degree of homology in their genomes, it is possible that P. hemiculteri displays high species complexity. Similar high species complexity has been shown in marine capsalid monogeneans [37] and freshwater gyrodactylid monogeneans [14]. Both these studies concluded species complexity based on detailed knowledge of the species’ morphological features, combined with high marker similarity during molecular analysis. However, our molecular data could also suggest the existence of cryptic species within Paradiplozoon, as has recently been discovered in other monogenean genera such as Gyrodactylus [19,29]. In these studies, while the main morphological characters of the Gyrodactylus species/lineages (anchor hooks, marginal hooks, ventral bars, marginal hook sickles) were difficult to separate, molecular data (complete cytochrome oxidase I and ITS2 genes) clearly indicated different genotypes of cryptic species. The lack of published morphological descriptions for Chinese diplozoons is a major hindrance for this study as it means these hypotheses cannot be reliably confirmed or refuted at this time. This highlights the importance of combining accurate morphological analysis with molecular analysis of markers as the main means of species identification.

In conclusion, this study provides an accurate redescription of P. hemiculteri, thereby addressing the absence of type material and inaccuracies in the original illustrations and sequence clasifications that have been the norm up until now. Our results confirm P. hemiculteri (Diplozoidae) as the only diplozoid demonstrably parasitising the gills of its Asian fish host, H. leucisculus.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgements

This research was supported by the Czech Science Foundation (Grant Nos. GBP505/12/G112, P506/12/1258), Masaryk University (Grant No. MUNI/A/1362/2016) and through Charles University institutional/departmental support (Grant Nos. UNCE 204017, PRVOUK P41, SVV 260319/2016). Computational resources were provided by CESNET LM2015042 and the CERIT Scientific Cloud LM2015085 under the programme “Projects of Large Research, Development and Innovation Infrastructure”. The research of DXJ was supported by the National Natural Science Foundation of China (Grant Nos. 31172051, 31572232) and visiting scholar grants of the South China Normal University. Our thanks are also due to reviewers and Editor-in-Chief, who significantly improved the final version of this manuscript.

References

  1. Ahmad F, Fazili KM, Sofi TA, Sheikh BA, Waza AA, Rashid R, Gani TT. 2015. Morphological and molecular characterization of Diplozoon kashmirensis; D. aegyptensis and D. guptai collected from fishes of Kashmir Valley- India. Fishery and Aquaculture Journal 6, 147. [Google Scholar]
  2. Bachellerie JP, Qu IH. 1993. Ribosomal RNA probes for detection and identification of species. In: Hyde JE, editor. In Protocols in Molecular Parasitology. Humana Press, Totowa, New Jersey. p. 249–263. [CrossRef] [Google Scholar]
  3. Bai JP, Wang JJ, Li J, Xu WJ, Fan LX. 2014. A new species of genus Paradiplozoon parasitic in Sikukia flavicaudata from the Lancang River, Xishuangbanna, Yunnan. Sichuan Journal of Zoology 33, 540–544. [Google Scholar]
  4. Boeger WA, Kritsky DC. 2001. Phylogenetic relationships of the Monogenoidea, in: Interrelationships of the Platyhelminthes, Littlewood DTJ, Bray RA, Eds. Taylor and Francis: London C & New York. p. 92–102. [Google Scholar]
  5. Bychowsky B, Nagibina L. 1967. New Capsalidae (Monogenoidea) from Pacific fishes. Parasitologiya 1, 521–527 [In Russian]. [Google Scholar]
  6. Chen C. 1973. An illustrated guide to the fish diseases and causative pathogenic fauna and florain the Hubei Province. (Chen C, editor.). Science Publishing House, Beijing [Google Scholar]
  7. Civáňová K, Koyun M, Koubková B. 2013. The molecular and morphometrical description of a new diplozoid species from the gills of the Garra rufa (Heckel, 1843) (Cyprinidae) from Turkey − Including a commentary on taxonomic division of Diplozoidae. Parasitology Research 112, 3053–3062. [CrossRef] [PubMed] [Google Scholar]
  8. Ergens R. 1969. The suitability of amonium picrate-glycerine in preparing slides of lower monogenoidea. Folia Parasitologica (Praha), 30, 320. [Google Scholar]
  9. Gao Q, Chen MX, Yao WJ, Gao Y, Song Y, Wang GT, Wang MX, Nie P. 2007. Phylogeny of diplozoids in five genera of the subfamily Diplozoinae Palombi, 1949 as inferred from ITS-2 rDNA sequences. Parasitology 134, 695–703. [CrossRef] [PubMed] [Google Scholar]
  10. Gelnar M, Koubkova B, Plankova H, Jurajda P. 1994. Report on metazoan parasites of fishes of the river Morava with remarks on the effects of water pollution. Helmithologia 31, 47–56. [Google Scholar]
  11. Gläser HJ, Gläser B. 1964. Zur Taxonomie der Gattung Diplozoon Nordmann, 1832. Zeitschrift für Parasitenkunde 25, 164–192. [Google Scholar]
  12. Guindon S, Gascuel O. 2003. A simple, fast, and accurate method to estimate large phylogenies by maximum likelihood. Systematic Biology 52, 696–704. [CrossRef] [PubMed] [Google Scholar]
  13. Huelsenbeck JP, Ronquist F, Nielsen R, Bollback JP. 2001. Bayesian inference of phylogeny and its impact on evolutionary biology. Science 294, 2310–2314. [CrossRef] [PubMed] [Google Scholar]
  14. Huyse T, Poulin R, Théron A. 2005. Speciation in parasites: a population genetics approach. Trends in Parasitology 21, 469–475. [CrossRef] [PubMed] [Google Scholar]
  15. Katoh K, Kuma KI, Toh H, Miyata T. 2005. MAFFT version 5: Improvement in accuracy of multiple sequence alignment. Nucleic Acids Research 33, 511–518. [CrossRef] [PubMed] [Google Scholar]
  16. Kearn G. 2011. Monogeneans the ultimate fish parasites. Biologist 58, 29–32. [Google Scholar]
  17. Kearse M, Moir R, Wilson A, Stones-Havas S, Cheung M, Sturrock S, Buxton S, Cooper A, Markowitz S, Duran C, et al. 2012. Geneious Basic: An integrated and extendable desktop software platform for the organization and analysis of sequence data. Bioinformatics 28, 1647–1649. [CrossRef] [PubMed] [Google Scholar]
  18. Khotenovsky IA. 1985. Suborder Discocotylinea Bychowsky, 1957. In: Bauer ON editor. Key to Parasites of Freshwater Fish. Fauna of the USSR. Izdatel’stvo ’ Nauka, ’ Leningrad. p. 354–387. (In Russian) [Google Scholar]
  19. Kuusela J, Ziętara M, Lumme J. 2008. Description of three new European cryptic species of Gyrodactylus Nordmann, 1832 supported by nuclear and mitochondrial phylogenetic characterization. Acta Parasitologica 53, 120–126. [CrossRef] [Google Scholar]
  20. Malmberg G. 1957. Om förekomsten av Gyrodactylus på svenska fiskar. Skrifter Utgivna av Södra Sveriges Fiskeriförening, Årsskrift, 1956, 19-76. (In Swedish) [Google Scholar]
  21. Matějusová I, Koubková B, Cunningham CO. 2004. Identification of European diplozoids (Monogenea, Diplozoinae) by restriction digestion of the ribosomal RNA internal transcribed spacer. Journal of Parasitology 90, 817–822. [Google Scholar]
  22. Matějusová I, Koubková B, D’Amelio S, Cunningham CO. 2001. Genetic characterization of six species of diplozoids (Monogenea; Diplozoidae). Parasitology 123, 465–474. [CrossRef] [PubMed] [Google Scholar]
  23. Matějusová I, Koubková B, Gelnar M, Cunningham CO. 2002. Paradiplozoon homoion Bychowsky & Nagibina, 1959 versus P. gracile Reichenbach-Klinke, 1961 (Monogenea): two species or phenotypic plasticity? Systematic Parasitology 53, 39–47. [CrossRef] [PubMed] [Google Scholar]
  24. Milne SJ, Avenant-Oldewage A. 2012. Seasonal growth of the attachment clamps of a Paradiplozoon sp. as depicted by statistical shape analysis. African Journal of Biotechnology 11, 2333–2339. [CrossRef] [Google Scholar]
  25. Nylander JAA, Wilgenbusch JC, Warren DL, Swofford DL. 2008. AWTY (are we there yet?): A system for graphical exploration of MCMC convergence in Bayesian phylogenetics. Bioinformatics 24, 581–583. [Google Scholar]
  26. Pečínková M, Vøllestad LA, Koubková B, Huml J, Jurajda P, Gelnar M. 2007. The relationship between developmental instability of gudgeon Gobio gobio and abundance or morphology of its ectoparasite Paradiplozoon homoion (Monogenea). Journal of Fish Biology 71, 1358–1370. [Google Scholar]
  27. Posada D. 2008. jModelTest: Phylogenetic model averaging. Molecular Biology and Evolution 25, 1253–1256. [Google Scholar]
  28. Rambaut A. 2009. FigTree v1.3.1. 2006-2009. Accessed November 29, 2012: Program package available at http://tree.bio.ed.ac [Google Scholar]
  29. Razo-Mendivil U, García-Vásquez A, Rubio-Godoy M. 2016. Spot the difference: Two cryptic species of Gyrodactylus von Nordmann, 1832 (Platyhelminthes: Monogenea) infecting Astyanax aeneus (Actinopterygii, Characidae) in Mexico. Parasitology International 65, 389–400. [Google Scholar]
  30. Ronquist F, Huelsenbeck JP. 2003. MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics 19:1572–1574. [Google Scholar]
  31. Dos Santos QM, Avenant-Oldewage A. 2015. Soft tissue digestion of Paradiplozoon vaalense for SEM of sclerites and simultaneous molecular analysis. Journal of Parasitology 101, 94–97. [Google Scholar]
  32. Dos Santos QM, Avenant-Oldewage A. 2016. The description of a new diplozoid species, Paradiplozoon krugerense n. sp., from Labeo rosae Steindachner, 1894 and Labeo congoro Peters, 1852 in the Kruger National Park, South Africa with notes on the effect of water quality on its infection variables. Hydrobiologia 777, 225–241. [Google Scholar]
  33. Shimazu T, Kobayashi K, Tojo K. 2015. Paradiplozoon skrjabini (Monogenea, Diplozoidae), an ectoparasite on the gills of freshwater fishes (Cyprinidae, Leuciscinae) of Japan and Primorsky Region, Russia: a morphological and molecular study. Bulletin of the National Museum of Nature and Science, Series A 41, 137–154. [Google Scholar]
  34. Sicard M, Desmarais E, Vigneux F, Shimazu T, Lambert A. 2003. Molecular phylogeny of the Diplozoidae (Monogenea, Polyopisthocotylea) parasitising 12 species of Cyprinidae (Teleostei): new data about speciation. in: Taxonomie, écologie et évolution des Métazoaires parasites. Taxonomy, Ecology and Evolution of Metazoan Parasites. Livre-hommage à Louis Euzet, Combes C, Jourdane J, Eds. Presses Universitaire de Perpignan: Perpignan p. 199–211. [Google Scholar]
  35. Smyth JD, Halton DW. 1983. The Physiology of Trematodes. Cambridge University Press [Google Scholar]
  36. Wang X, Jiao L, Yao WJ, Hao CL, Yue C. 2015. The first record of a newly reported Chinese Diplozoidae of Monogenea on fishes in the Ergis River. Acta Hydrobiologica Sinica 39, 794–797. [Google Scholar]
  37. Whittington ID. 2004. The Capsalidae (Monogenea: Monopisthocotylea): A review of diversity, classification and phylogeny with a note about species complexes. Folia Parasitologica (Praha) 51, 109–122. [Google Scholar]
  38. Whittington ID, Cribb BW, Hamwood TE, Halliday JA. 2000. Host-specificity of monogenean (platyhelminth) parasites: A role for anterior adhesive areas? International Journal for Parasitology 30, 305–320. [Google Scholar]
  39. Wu BH, Long S, Wang WJ. 2000. Fauna Sinica: Platyhelminthes Monogenea. Science Press, Beijing, China. [Google Scholar]
  40. Zavodna M, Sandland GJ, Minchella DJ. 2008. Effects of intermediate host genetic background on parasite transmission dynamics: a case study using Schistosoma mansoni. Experimental Parasitology 120, 57–61. [Google Scholar]

Cite this article as: Jirsová D, Ding X, Civáňová K, Jirounková E, Ilgová J, Koubková B, Kašný M, Gelnar M. 2018. Redescription of Paradiplozoon hemiculteri (Monogenea, Diplozoidae) from the type host Hemiculter leucisculus, with neotype designation. Parasite 25, 4

All Tables

Table 1

GenBank ITS2 sequences of monogenean species selected for phylogenetic analysis. Paradiplozoon hemiculteri GenBank sequences are marked with an asterisk; data obtained for this study are also underlined. Outgroup sequence of Inustiatus inustiatus is in bold.

In the text

All Figures

thumbnail Figure 1

Paradiplozoon hemiculteri. A) Overall total; B) Detail of the two rows of clamps on the opisthaptor.
In the text
thumbnail Figure 2

Paradiplozoon hemiculteri clamp. A) Clamp morphology (scale bar = 50 μm); a) anterior end of median plate, b) trapeze spur, c) anterior joining sclerite, d) proximal tip of anterior jaw, e) posterior end of median with a wide rounded sclerite, f) posterior joining sclerite, g) medial sclerite of posterior jaw, i) lateral sclerite of posterior jaw. B) Central hook sickle (scale bar = 20 μm).
In the text
thumbnail Figure 3

Concatenated phylogenetic tree based on ITS2 sequences for selected diplozoids. Constructed using MrBayes software, the tree includes results for Bayesian inference and maximum-likelihood with PP/bootstrap branch support. Genetic distance between our sequence data is listed below the branch support. Sequences of Paradiplozoon hemiculteri previously stored in GenBank are marked with an asterisk. Data obtained for this study are highlighted by grey gradient.
In the text

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.