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Biological Reviews of the Cambridge... May 1974
Comparative Study Review
Topics: Animals; Echinococcus; Fasciola; Fasciola hepatica; Invertebrates; Platyhelminths; Water-Electrolyte Balance
PubMed: 4604982
DOI: 10.1111/j.1469-185x.1974.tb01572.x -
Parasite (Paris, France) 2022Polystomatids are platyhelminth parasites that infect mainly amphibians and freshwater turtles. For more than seven decades, chelonian polystomes were classified into...
Revision of the systematics of the Polystomoidinae (Platyhelminthes, Monogenea, Polystomatidae) with redefinition of Polystomoides Ward, 1917 and Uteropolystomoides Tinsley, 2017.
Polystomatids are platyhelminth parasites that infect mainly amphibians and freshwater turtles. For more than seven decades, chelonian polystomes were classified into three genera according to the number of hamuli, i.e. absent for Neopolystoma, one pair for Polystomoidella and two pairs for Polystomoides. Following re-examination of morphological characters, seven new genera were erected the past six years, namely Apaloneotrema, Aussietrema, Fornixtrema, Manotrema, Pleurodirotrema, Uropolystomoides and Uteropolystomoides. However, the polyphyly of Neopolystoma and Polystomoides on the one hand, and the nested position of Uteropolystomoides within a clade encompassing all Neopolystoma and Polystomoides spp. on the other, still raised questions about the validity of these genera. We therefore re-examined several types, paratypes and voucher specimens, and investigated the molecular phylogeny of polystomes sampled from the oral cavity of North American turtles to re-evaluate their systematic status. We show that all Polystomoides Ward, 1917, sensu Du Preez et al., 2022, Neopolystoma Price, 1939, sensu Du Preez et al., 2022 and Uteropolystomoides Tinsley, 2017 species, display vaginae that are peripheral and extend well beyond the intestine. We thus reassign all species of the clade to Polystomoides and propose nine new combinations; however, although Uteropolystomoides is nested within this clade, based on its unique morphological features, we propose to keep it as a valid taxon. Polystomoides as redefined herein groups all polystome species infecting either the oral cavity or the urinary bladder of cryptodires, with peripheral vaginae and with or without two pairs of small hamuli. Uteropolystomoides nelsoni (Du Preez & Van Rooyen 2015), originally described from Pseudemys nelsoni Carr is now regarded as Uteropolystomoides multifalx (Stunkard, 1924) n. comb. infecting three distinct Pseudemys species of North America.
Topics: Animals; Trematoda; Platyhelminths; Phylogeny; Parasites; Urinary Bladder; Turtles
PubMed: 36562437
DOI: 10.1051/parasite/2022056 -
Zootaxa Aug 2019Specimens of Bipalium adventitium (Platyhelminthes, Geoplanidae) were found in Montréal, Québec, Canada. The specimens showed the typical colour pattern of the species...
Specimens of Bipalium adventitium (Platyhelminthes, Geoplanidae) were found in Montréal, Québec, Canada. The specimens showed the typical colour pattern of the species and barcoding (Cytochrome Oxidase I) demonstrated near-identity with a sequence of the same species from the USA. This is the first record of the species in Canada.
Topics: Animals; Canada; Platyhelminths
PubMed: 31716820
DOI: 10.11646/zootaxa.4656.3.13 -
Folia Parasitologica Nov 2022Taxonomic issues within Trypanorhyncha, e.g., the inaccurate light microscopic visualisation of the hook patterns, are solvable by confocal laser scanning microscopy...
Confocal laser scanning microscopy (CLSM) as a new tool for morphological characterisation of both newly collected and museum voucher specimens of the Trypanorhyncha Diesing, 1863 (Platyhelminthes: Cestoda).
Taxonomic issues within Trypanorhyncha, e.g., the inaccurate light microscopic visualisation of the hook patterns, are solvable by confocal laser scanning microscopy (CLSM). We applied CLSM imaging to study Trygonicola macropora (Shipley et Hornell, 1906) and Dollfusiella michiae (Southwell, 1929) from Neotrygon caeruliopunctata Last, White et Séret from Bali, Indonesia. To illustrate the strength and limitations of CLSM, images of Otobothrium cysticum (Mayer, 1842) and Symbothriorhynchus tigaminacantha Palm, 2004, both permanent mounts from a collection, were also processed. The CLSM created image stacks of many layers, and edited with IMARIS Software, these layers resulted in three-dimensional images of the armature patterns and internal organs of both species. BABB (benzylalcohol and benzylbenzuolate) clearing was applied to T. macropora. We conclude that trypanorhynch cestodes stained with Mayer-Schuberg's acetic carmine permanently mounted in Canada balsam are suitable for CLSM, allowing detailed analyses of museum type-material as well as freshly collected and processed worms. BABB resulted in imaging the testes in detail, suggesting other stains to be used for CLSM in trypanorhynch cestode research. Application of CLSM for studies of other cestode groups is highly recommended.
Topics: Animals; Cestoda; Microscopy, Confocal; Museums; Platyhelminths; Skates, Fish
PubMed: 36458586
DOI: 10.14411/fp.2022.026 -
Molecular Phylogenetics and Evolution Apr 2020The planarian suborder Cavernicola Sluys, 1990 was originally created to house five species of triclad flatworms with special morphological features and a surprisingly...
The planarian suborder Cavernicola Sluys, 1990 was originally created to house five species of triclad flatworms with special morphological features and a surprisingly discontinuous and broad geographic distribution. These five species could not be accommodated with any degree of certainty in any of the three taxonomic groups existing at that moment, viz., Paludicola Hallez, 1892, Terricola Hallez, 1892, and Maricola Hallez, 1892. The scarce representation of the group and the peculiarities of the morphological features of the species, including several described more recently, have complicated new tests of the monophyly of the Cavernicola, the assessment of its taxonomic status, as well as the resolution of its internal relationships. Here we present the first molecular study including all genera currently known for the group, excepting one. We analysed newly generated 18S and 28S rDNA data for these species, together with a broad representation of other triclad flatworms. The resulting phylogenetic trees supported the monophyly of the Cavernicola, as well as its sister-group relationship to the Maricola. The sister-group relationship to the Maricola and affinities within the Cavernicola falsify the morphology-based phylogeny of the latter that was proposed previously. The relatively high diversity of some cavernicolan genera suggests that the presumed rarity of the group actually may in part be due to a collecting artefact. Ancestral state reconstruction analyses suggest that the ancestral habitat of the group concerned epigean freshwater conditions. Our results point to an evolutionary scenario in which the Cavernicola (a) originated in a freshwater habitat, (b) as the sister clade of the marine triclads, and (c) subsequently radiated and colonized both epigean and hypogean environments. Competition with other planarians, notably members of the Continenticola, or changes in epigean habitat conditions are two possible explanations -still to be tested- for the loss of most epigean diversity of the Cavernicola, which is currently reflected in their highly disjunct distributions.
Topics: Animals; Bayes Theorem; Biological Evolution; Caves; Ecosystem; Phylogeny; Phylogeography; Platyhelminths; RNA, Ribosomal, 18S; RNA, Ribosomal, 28S
PubMed: 31862459
DOI: 10.1016/j.ympev.2019.106709 -
Zootaxa Jul 2023We describe Cycloporus pinkipus sp. n., a new polyclad flatworm species from the Adriatic coast of Croatia using live images, histological sections, and a molecular...
We describe Cycloporus pinkipus sp. n., a new polyclad flatworm species from the Adriatic coast of Croatia using live images, histological sections, and a molecular marker. It is the fifteenth described species of Cycloporus Lang, 1884 and the second described congener in the Mediterranean. The genus Cycloporus is characterised by a small oval body, tentacular bumps and the name-giving marginal pores. Cycloporus pinkipus sp. n. has a smooth dorsal surface, which is transparent creamy white with light brown to yellow spots, covered with prominent serial pink spots on the inner rim of the body margin. There is little variation of the genital organs between different species of the genus, therefore we recognise C. pinkipus sp. n. as a new species in particular due to its unique coloration, and a unique partial large nuclear ribosomal subunit (28S) sequence. In recent years the family Euryleptidae Stimpson, 1857, which also contains the genus Cycloporus, was discussed and revised in several molecular studies. In an updated molecular phylogeny of the Polycladida based on partial 18S and 28S rDNA marker genes, C. pinkipus sp. n. was recovered in a clade of many other Cycloporus species within Euryleptidae.
Topics: Animals; Phylogeny; Platyhelminths; DNA, Ribosomal
PubMed: 37518236
DOI: 10.11646/zootaxa.5319.2.5 -
Advances in Experimental Medicine and... 2010Parasitic worms come from two distinct, distant phyla, Nematoda (roundworms) and Platyhelminthes (flatworms). The nervous systems of worms from both phyla are replete... (Review)
Review
Parasitic worms come from two distinct, distant phyla, Nematoda (roundworms) and Platyhelminthes (flatworms). The nervous systems of worms from both phyla are replete with neuropeptides and there is ample physiological evidence that these neuropeptides control vital aspects of worm biology. In each phyla, the physiological evidence for critical roles for helminth neuropeptides is derived from both parasitic and free-living members. In the nematodes, the intestinal parasite Ascaris suum and the free-living Caenorhabditis elegans have yielded most of the data; in the platyhelminths, the most physiological data has come from the blood fluke Schistosoma mansoni. FMRFamide-like peptides (FLPs) have many varied effects (excitation, relaxation, or a combination) on somatic musculature, reproductive musculature, the pharynx and motor neurons in nematodes. Insulin-like peptides (INSs) play an essential role in nematode dauer formation and other developmental processes. There is also some evidence for a role in somatic muscle control for the somewhat heterogeneous grouping ofpeptides known as neuropeptide-like proteins (NLPs). In platyhelminths, as in nematodes, FLPs have a central role in somatic muscle function. Reports of FLP physiological action in platyhelminths are limited to a potent excitation of the somatic musculature. Platyhelminths are also abundantly endowed with neuropeptide Fs (NPFs), which appear absent from nematodes. There is not yet any data linking platyhelminth NPF to any particular physiological outcome, but this neuropeptide does potently and specifically inhibit cAMP accumulation in schistosomes. In nematodes and platyhelminths, there is an abundance of physiological evidence demonstrating that neuropeptides play critical roles in the biology of both free-living and parasitic helminths. While it is certainly true that there remains a great deal to learn about the biology of neuropeptides in both phyla, physiological evidence presently available points to neuropeptidergic signaling as a very promising field from which to harvest future drug targets.
Topics: Amino Acid Sequence; Animals; Ascaris; Helminths; Locomotion; Muscle, Skeletal; Nematoda; Neuropeptides; Platyhelminths; Posture
PubMed: 21189675
DOI: 10.1007/978-1-4419-6902-6_5 -
Zootaxa Nov 2022
Topics: Animals; Platyhelminths; South America
PubMed: 37045418
DOI: 10.11646/zootaxa.5205.5.8 -
Molecular and Biochemical Parasitology Sep 2021The phenomenon of non-uniform usage of the synonymous codons, where some codons are given more preference to others, is known as codon usage bias (CUB). CUB is known to...
The phenomenon of non-uniform usage of the synonymous codons, where some codons are given more preference to others, is known as codon usage bias (CUB). CUB is known to be determined by two major evolutionary forces i.e. mutation pressure and selection. We used various approaches to understand the codon usage pattern in mitochondrial CO (MT-CO) genes involved in complex IV of the respiratory chain (RC) as no work was reported yet. Our present study revealed that CUB was relatively high and the coding sequences were rich in A and T. Correspondence analysis further indicated that A/T compositional properties under mutational pressure might be affecting the codon usage pattern and was different in different classes for MT-CO gene. A highly significant correlation between A% and A3%, T% and T3%, G% and G3%, C% and C3%, GC% and GC3% in all the classes indicated that compositional constraints under mutational pressure and natural selection might affect the CUB. Neutrality plot indicated that both natural selection and mutational bias affected the CUB, where, natural selection played the major role as compared to mutational pressure.
Topics: Animals; Codon; Codon Usage; Genes, Mitochondrial; Platyhelminths; Selection, Genetic
PubMed: 34487743
DOI: 10.1016/j.molbiopara.2021.111410 -
Zootaxa Jan 2017The present contribution provides the first faunistic and taxonomic account of six species of land flatworm from the island of São Tomé, including five new species of...
The present contribution provides the first faunistic and taxonomic account of six species of land flatworm from the island of São Tomé, including five new species of the genus Othelosoma Gray, 1869 and the introduced Bipalium kewense Moseley, 1878. One of the new species represents the first African land flatworm that has specks on its dorsal body surface, instead of stripes or a more or less uniform colouration. At least two of the new species were observed to prey on snails. The study details the fourth record of a sclerotic spermatophore in a species of land flatworm, and discusses the definition and homology of double female genital canals in African and Indian species of the genus Othelosoma.
Topics: Animals; Female; Platyhelminths
PubMed: 28187665
DOI: 10.11646/zootaxa.4221.3.2