-
Temnocephalan epibionts (Platyhelminthes, Temnocephalida) on mollusks from Pantanal wetland, Brazil.Zootaxa Oct 2020Temnocephala iheringi Haswell, 1893 was recorded in Marisa planogyra Pilsbry, 1933 and Pomacea maculata Perry, 1810. Also, Temnocephala amatoi sp. nov. was described...
Temnocephala iheringi Haswell, 1893 was recorded in Marisa planogyra Pilsbry, 1933 and Pomacea maculata Perry, 1810. Also, Temnocephala amatoi sp. nov. was described from Pomacea scalaris (d'Orbigny, 1835). The mollusks were collected from temporary ponds at Ypiranga Farm, Poconé, Mato Grosso, Brazil. The new species differs from six other species of Temnocephala Blanchard, 1849 epibionts on molluks by having the following combination of characters: 1. a short and curved cirrus; 2. a narrow introvert with approximately 22 longitudinal rows of spines with 13 spines each; 3. internal spines with a narrow base, longer on the base of the introvert and smaller in the distal portion; 4. a single and asymmetrical vaginal sphincter and; 5. elliptical, longer than wide epidermal 'excretory' syncytial plates (EPs) with a excretory pore displaced to the anterior portion of the plate. Temnocephala lamothei Damborenea Brusa, 2008 has a curved cirrus, similar in size to the new species' cirrus. However, the introvert is not swollen with an oblique proximal margin, marked with a thickened oblique ring and two rows of 45-50 thin spines, differentiating the species from T. amatoi sp. nov.. When comparing the specimens of T. iheringi from Poconé with the redescription of the species from Southern Brazil previously published by the authors, we found significant intraspecific variation in the size of the adhesive disk, pharynx length, shaft and introvert length, spines of the introvert length, as well as differences in the number of paranephrocytes. The size of the EPs and, when comparing with published data from Uruguayan and Argentinean specimens, the body size also showed important differences. We hypothesize that the host species may be the cause of the intraspecific variations found. Overall, the record of two new hosts for T. iheringi, the intraspecific variation found in this species and its geographical distribution being expanded 418 km further to the north, together with the description of a new species, add acknowledgment to the Rhabdocoela fauna in the Brazilian Pantanal.
Topics: Animals; Brazil; Female; Mollusca; Platyhelminths; Turbellaria; Wetlands
PubMed: 33056218
DOI: 10.11646/zootaxa.4858.3.2 -
Microscopy Research and Technique Aug 1992The flatworms (Platyhelminthes) and the round worms (Nematoda) are phyla exhibiting strikingly different levels of cellular organization. In both, sensilla are composed... (Review)
Review
The flatworms (Platyhelminthes) and the round worms (Nematoda) are phyla exhibiting strikingly different levels of cellular organization. In both, sensilla are composed of the endings of sensory dendrites intercalated into their epidermis. In flatworms, sensilla that penetrate the syncytial epidermis bear sensory processes derived from cilia. In free-living species, the sensory processes more closely resemble motile cilia, while in parasites, greater deviations occur from the classical cilium pattern. Estimates of the function of the various sensilla have been largely arbitrary, and remain based on ultrastructural features. Sensilla in round worms lie below or within a heavy secreted cuticle. Two glia-like cell types occur. The socket cell mediates contact with cuticle and is responsible for cuticular modifications essential for operation of the sensillum. The sheath cell forms a receptor cavity around the sensory processes and regulates its environment. Sensory processes vary greatly from the classical cilium pattern. Absence of a basal body, but preservation of a ciliary necklace, suggests that the latter has a primary importance in sensory transduction. Estimates of function are based largely on ultrastructural features and analogies to arthropod sensilla. Genetic studies with the free-living nematode Caenorhabditis are beginning to demonstrate details of function and development. Speculations on the roles of basal bodies, rootlets, and vesicles and on the significance of recessed sensilla are given.
Topics: Animals; Biological Evolution; Cilia; Microscopy, Electron; Microscopy, Electron, Scanning; Nematoda; Platyhelminths; Sense Organs
PubMed: 1504355
DOI: 10.1002/jemt.1070220306 -
Marine Biotechnology (New York, N.Y.) Dec 2020Tetrodotoxin (TTX), also known as pufferfish toxin, causes a respiratory disorder by blocking neurotransmission, with voltage-gated sodium channel inhibition on muscle...
Tetrodotoxin (TTX), also known as pufferfish toxin, causes a respiratory disorder by blocking neurotransmission, with voltage-gated sodium channel inhibition on muscle and nerve tissues. The toxin is widely distributed across vertebrates, invertebrates and bacteria. Therefore, it is generally thought that TTX in pufferfish accumulates via the food webs, beginning with marine bacteria as a primary producer. Polyclad flatworms in the genus Planocera are also known to be highly toxic, TTX-bearing organisms. Unlike the case of pufferfish, the source of TTX in these flatworms is unknown. In this study, taxonomical distribution patterns of TTX were investigated for acotylean flatworms from coastal waters using molecular phylogenetic analysis and high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). A maximum likelihood tree based on the 28S rRNA gene sequence showed that the flatworms belonged to several different lineages among the genera Planocera, Stylochus, Paraplanocera, Discocelis, Notocomplana, Notoplana, Callioplana and Peudostylochus. After LC-MS/MS analysis, the distribution of TTX was mapped onto the molecular phylogenetic tree. TTX-bearing flatworm species were seen to be restricted to specific Planocera lineages, suggesting that the TTX-bearing flatworm species have common genes for TTX-accumulating mechanisms.
Topics: Animals; Japan; Phylogeny; Platyhelminths; RNA, Ribosomal, 28S; Tetrodotoxin
PubMed: 32415408
DOI: 10.1007/s10126-020-09968-1 -
identification of tetraspanins in monopisthocotylean (Platyhelminthes: Monogenea) parasites of fish.Journal of Helminthology Mar 2022Tetraspanins are a superfamily of transmembrane proteins that in flatworms have structural roles in the development, maturation or stability of the tegument. Several...
Tetraspanins are a superfamily of transmembrane proteins that in flatworms have structural roles in the development, maturation or stability of the tegument. Several tetraspanins are considered as potential candidates for vaccines or drugs against helminths. Monopisthocotylean monogeneans are ectoparasites of fish that are health hazards for farmed fish. The aim of this study was to identify in silico putative tetraspanins in the genomic datasets of four monopisthocotylean species. The analysis predicted and classified 40 tetraspanins in Rhabdosynochus viridisi, 39 in Scutogyrus longicornis, 22 in Gyrodactylus salaris and 13 in Neobenedenia melleni, belonging to 13 orthologous groups. The high divergence of tetraspanins made it difficult to annotate their function. However, a conserved group was identified in different metazoan taxa. According to this study, metazoan tetraspanins can be divided into 17 monophyletic groups. Of the 114 monogenean tetraspanins, only seven were phylogenetically close to tetraspanins from non-platyhelminth metazoans, which suggests that this group of proteins shows rapid sequence divergence. The similarity of the monopisthocotylean tetraspanins was highest with trematodes, followed by cestodes and then free-living platyhelminths. In total, 27 monopisthocotylean-specific and 34 flatworm-specific tetraspanins were identified. Four monogenean tetraspanins were orthologous to TSP-1, which is a candidate for the development of vaccines and a potential pharmacological target in trematodes and cestodes. Although studies of tetraspanins in parasitic flatworms are scarce, this is an interesting group of proteins for the development of new methods to control monogeneans.
Topics: Animals; Fish Diseases; Fishes; Phylogeny; Platyhelminths; Tetraspanins
PubMed: 35321773
DOI: 10.1017/S0022149X22000098 -
Molecular Phylogenetics and Evolution Nov 2013Platyzoa is a putative lophotrochozoan (spiralian) subtaxon within the protostome clade of Metazoa, comprising a range of biologically diverse, mostly small worm-shaped... (Review)
Review
Platyzoa is a putative lophotrochozoan (spiralian) subtaxon within the protostome clade of Metazoa, comprising a range of biologically diverse, mostly small worm-shaped animals. The monophyly of Platyzoa, the relationships between the putative subgroups Platyhelminthes, Gastrotricha and Gnathifera (the latter comprising at least Gnathostomulida, "Rotifera" and Acanthocephala) as well as some aspects of the internal phylogenies of these subgroups are highly debated. Here we review how complete mitochondrial (mt) genome data contribute to these debates. We highlight special features of the mt genomes and discuss problems in mtDNA phylogenies of the clade. Mitochondrial genome data seem to be insufficient to resolve the position of the platyzoan clade within the Spiralia but can help to address internal phylogenetic questions. The present review includes a tabular survey of all published platyzoan mt genomes.
Topics: Acanthocephala; Animals; DNA, Mitochondrial; Evolution, Molecular; Gene Order; Genetic Code; Genome, Mitochondrial; Invertebrates; Phylogeny; Platyhelminths; Rotifera; Sequence Analysis, DNA
PubMed: 23274056
DOI: 10.1016/j.ympev.2012.12.015 -
Development Genes and Evolution Jan 2008Pumilio proteins are proposed to have a conserved primordial function in the maintenance of proliferation in stem cells through post-transcriptional regulation. In this... (Comparative Study)
Comparative Study
Pumilio proteins are proposed to have a conserved primordial function in the maintenance of proliferation in stem cells through post-transcriptional regulation. In this work, a search for pumilio homology domain (PUM-HD) sequences of pumilio genes from several Platyhelminthes species was performed, including representatives form Cestoda, Trematoda and Tricladida. Only one PUM-HD sequence was found in each triclad species; however, two PUM-HD homologues were found in all the parasitic species. These sequences formed two clearly separated clades: PlatyPum1, with sequences from all species, and PlatyPum2, composed exclusively of neodermatan sequences. Therefore, at least one duplication of the pumilio gene must have occurred before the divergence of cestodes and trematodes. Further duplications of PUM-HD were found in Fasciola hepatica, but these consist of retropseudogenes. This is the first comparative analysis of PUM-HD sequences in the Platyhelminthes and, more generally, in any lophotrochozoan phylum.
Topics: Amino Acid Sequence; Animals; Base Sequence; Computational Biology; Molecular Sequence Data; Phylogeny; Platyhelminths; Protein Structure, Tertiary; RNA-Binding Proteins; Reverse Transcriptase Polymerase Chain Reaction; Sequence Alignment; Sequence Analysis, DNA; Transcription Factors
PubMed: 18180952
DOI: 10.1007/s00427-007-0200-1 -
Molecular Phylogenetics and Evolution Jan 2022Free-living flatworms of the genus Macrostomum are small and transparent animals, representing attractive study organisms for a broad range of topics in evolutionary,...
Free-living flatworms of the genus Macrostomum are small and transparent animals, representing attractive study organisms for a broad range of topics in evolutionary, developmental, and molecular biology. The genus includes the model organism M. lignano for which extensive molecular resources are available, and recently there is a growing interest in extending work to additional species in the genus. These endeavours are currently hindered because, even though >200 Macrostomum species have been taxonomically described, molecular phylogenetic information and geographic sampling remain limited. We report on a global sampling campaign aimed at increasing taxon sampling and geographic representation of the genus. Specifically, we use extensive transcriptome and single-locus data to generate phylogenomic hypotheses including 145 species. Across different phylogenetic methods and alignments used, we identify several consistent clades, while their exact grouping is less clear, possibly due to a radiation early in Macrostomum evolution. Moreover, we uncover a large undescribed diversity, with 94 of the studied species likely being new to science, and we identify multiple novel morphological traits. Furthermore, we identify cryptic speciation in a taxonomically challenging assemblage of species, suggesting that the use of molecular markers is a prerequisite for future work, and we describe the distribution of putative synapomorphies and suggest taxonomic revisions based on our finding. Our large-scale phylogenomic dataset now provides a robust foundation for comparative analyses of morphological, behavioural and molecular evolution in this genus.
Topics: Animals; Evolution, Molecular; Phenotype; Phylogeny; Platyhelminths; Transcriptome
PubMed: 34438051
DOI: 10.1016/j.ympev.2021.107296 -
Parasite (Paris, France) 2023Ribosomal DNA sequences are currently available for 32 morphologically recognized species of Dactylogyrus parasitizing Nearctic cypriniforms, but only 16 of them are...
Nearctic Dactylogyrus species (Platyhelminthes, Monogenea) parasitizing cypriniform fishes in the context of morphology and phylogeny, with descriptions of seven new species.
Ribosomal DNA sequences are currently available for 32 morphologically recognized species of Dactylogyrus parasitizing Nearctic cypriniforms, but only 16 of them are assigned to nominal species. Herein, morphological data on 28 of the 32 species are provided, together with comments on their phylogenetic relationships in the context of the morphology of taxonomically important structures. Seven new species of Dactylogyrus are described from five species of leuciscids and one species of catostomids, as follows: D. aduncus n. sp. from Campostoma spadiceum, D. cloutmani n. sp. from Luxilus chrysocephalus isolepis, D. cornifrons n. sp. from Cyprinella venusta, D. fimbratus n. sp. from Rhinichthys cataractae, D. mcallisteri n. sp. from Semotilus atromaculatus, and D. chieni n. sp. and D. haneki n. sp. from Hypentelium nigricans. Four previously described species of Dactylogyrus, D. atromaculatus from S. atromaculatus, D. eos from C. neogaeus, D. parvicirrus from Notemigonus crysoleucas and D. perlus from L. c. isolepis, are redescribed and/or figured. As for the remaining 17 species, only the male copulatory organs (MCOs) taken from the respective hologenophores are illustrated. On the basis of phylogenetic analyses, two main clades of Nearctic Dactylogyrus were recognized and supported by the different morphology of the MCO. The first one included 22 strictly Nearctic species sharing the same MCO type with Dactylogyrus spp. parasitizing cyprinids likely of Asian origin. The second clade encompassed Dactylogyrus spp. with diverse MCO morphology and was placed in the sister position to Dactylogyrus spp. parasitizing European leuciscids and North-West African cyprinids.
Topics: Male; Animals; Phylogeny; Platyhelminths; Trematoda; Cypriniformes
PubMed: 37589452
DOI: 10.1051/parasite/2023032 -
Parazitologiia 2008Monogeneans parasitize 31 gudgeon species of 130, and 13 gudgeon genera of 30 known. Monogenea from gudgeon comprise 48 species of the genus Dactylogyrus, 1... (Review)
Review
Monogeneans parasitize 31 gudgeon species of 130, and 13 gudgeon genera of 30 known. Monogenea from gudgeon comprise 48 species of the genus Dactylogyrus, 1 Bivaginogyrus (Dactylogyridae), 18 Ancyrocephalus s. l. (Ancyrocephalidae), 6 Gyrodactylus (Gyrodactylidae), 3 Paradiplozoon, and 1 species of the genus Sindiplozoon (Diplozoidae). The following characters were used in the morphological analysis: (1) structure of the copulatory organ, (2) morphology of the anchors, marginal hooks and bars, (3) characteristic of attachment on gills. Among the Dactylogyrus species parasitizing gudgeon, 30 monophyletic species groups and 13 levels of morphological organization were established. The first level comprises dactylogyrids without the additional ventral bar of haptor. It includes species with the copulatory organ of pro-cryptomeres type. This type is ancestral for dactylogyrids of the Amur/China fauna. Levels II-IV; VI, etc. are derivates of level I. Levels VII-VIII can be characterized by the jamming type of attachment characteristic for Dactylogyrus sphyrna or D. anchoratus, when marginal hooks penetrate gill filaments towards the anchors. Levels IX-XII include species with the attachment by clasping, when the anchors directed towards each other. Some species groups of Dactylogyrus (V, XIII) switched onto gudgeons from other fishes (Cultrinae, Xenocyprininae, Hypophthalmichthinae). Species of the genus Ancyrocephalus s. l. form two levels of morphological organization and 8 monophyletic groups. Repeated switches of ancyrocephalids from freshwater gobies to gudgeons and their switches from gudgeons to other fishes were shown. Species of the genus Hemibarbus serve as hosts for morphologically peculiar species groups of Dactylogyrus and Ancyrocephalus s. l. We can conclude that gyrodactylids from gudgeons do not form a natural monophyletic group. This parasite fauna originated as a result of multiple switches from phylogenetically distant but ecologically similar hosts, for example sticklebacks, bitterlings, chars, spined loaches, etc. Species of the family Diplozoidae parasitizing gudgeons may invade also many species from other fish taxa.
Topics: Animals; Cyprinidae; Platyhelminths
PubMed: 19065839
DOI: No ID Found -
Parasite (Paris, France) 2023Twenty-nine dactylogyrid species were reported from teleosts collected during a survey of the parasites of fishes of Moreton Bay, Queensland, Australia, in 2016. Two new...
Species of Dactylogyridae (Platyhelminthes: Monogenoidea) infecting marine fishes of Moreton Bay, Queensland, Australia, with proposals of Pleuronectitrema n. gen. and Ecnomotrema n. gen. and descriptions of 13 new species.
Twenty-nine dactylogyrid species were reported from teleosts collected during a survey of the parasites of fishes of Moreton Bay, Queensland, Australia, in 2016. Two new genera, Ecnomotrema n. gen. and Pleuronectitrema n. gen., were proposed, and 13 new species were illustrated and described: Atherinicus difficilis n. sp., Diversohamulus similis n. sp., and Ecnomotrema cetiosum n. sp. from Atherinomorus vaigiensis; Haliotrema apiculum n. sp. from Pempheris schwenkii; Haliotrema tugulduriforme n. sp. from Scarus ghobban; Lethrinitrema australiense n. sp., and Lethrinitrema lituus n. sp. from Lethrinus nebulosus; Tetrancistrum siganioides n. sp. from Siganus fuscescens; Ligophorus bostrychus n. sp. from Planiliza subviridis; Neohaliotrema gemmula n. sp. from Abudefduf vaigiensis; Neohaliotrema moretonense n. sp. from Ab. vaigiensis and Ab. bengalensis; and Pleuronectitrema spirula n. sp. from Pseudorhombus arsius (all from Moreton Bay); Pleuronectitrema kuwaitense Kritsky & Sey n. sp. was described from specimens collected from P. arsius in Kuwait during 1996. Ten new host records were recorded: Chauhanellus duriensis Lim, 1994 and Hamatopeduncularia thalassini Bychowsky & Nagibina, 1969 from Pararius proximus; Diplectanotrema sp. 1 and sp. 2 from Sillago maculata and Goniistius vestitus, respectively; Diversohamulus tricuspidatus Bychowsky & Nagibina, 1969 from At. vaigiensis; Hal. cf. dempsteri (Mizelle & Price, 1964) Young, 1968 from Prionurus microlepidotus; Hal. spirale Yamaguti, 1968 from Upeneus tragula; Ligophorus kaohsianghsieni (Gussev, 1962) Gussev, 1985 from Planiliza subviridis; and Neohaliotrema malayense Lim & Gibson, 2010 from Ab. bengalensis and Ab. whitleyi. Twenty-five new faunal records for Moreton Bay were recorded, including the new species listed above and C. duriensis, Diplectanotrema sp. 1 and sp. 2, Diversohamulus tricuspidatus Bychowsky & Nagibina, 1969, Glyphidohaptor phractophallus Kritsky, Galli, & Yang, 2007, Hal. cf. dempsteri, Hal. johnstoni Bychowsky & Nagibina, 1970, Hal. spirale, Yamaguti, 1968 Hamatopeduncularia thalassini Bychowsky & Nagibina, 1969, Lethrinitrema nebulosum Sun, Li, & Yang, 2014, Ligophorus kaohsianghsieni (Gussev, 1962) Gussev, 1985, Ligophorus parvicopulatrix Soo & Lim, 2012, and Neohaliotrema malayense Lim & Gibson, 2010. Three new combinations were proposed: Hal. spariense Roubal, 1981 as Euryhaliotrema spariense (Roubal, 1981) n. comb.; and Hal. arsiosa Venkatanarasaiah, 1984 and Hal. youngi Venkatanarasaiah, 1984 as Pleuronectitrema arsiosa (Venkatanarasaiah, 1984) n. comb. and Pleuronectitrema youngi (Venkatanarasaiah, 1984) n. comb., respectively; Haliotrema sp. of Zhang is transferred to Pleuronectitrema as Pleuronectitrema sp. Hal. ctenochaeti Yamaguti, 1968 was replaced with Hal. asymphylum n. nom. to remove it from homonymy with Hal. ctenochaeti Young, 1968. Pseudohaliotrematoides zancli Yamaguti, 1968 was transferred to Haliotrema as Haliotrema hawaiiense n. nom. Hal. zancli Yamaguti, 1968 was considered a junior subjective synonym of Hal. dempsteri.
Topics: Animals; Queensland; Bays; Platyhelminths; Trematoda; Australia; Fishes; Smegmamorpha
PubMed: 38117271
DOI: 10.1051/parasite/2023053