<i>Urceolaria mitra</i> (von Seib) Epizoic on <i>Polycelis tenuis</i> (IJIMA) an SEM Study.

Bowen, I. D.; Ryder, Timothy A.

doi:10.1006/cbir.1994.1125

Cited by 6 publications

(2 citation statements)

References 11 publications

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“…Interestingly, Urceolaria and Trichodina can either occupy their hosts separately or they can co-occur as well ( Reynoldson, 1947 ). Both attach to their hosts with the aid of a skeletal ring, leaving a visible mark on the host surface ( Bowen and Ryder, 1994 ). The extensive work on ecology, dispersal, and population dynamics of U. mitra showed that mobilids only use the host-produced water currents for feeding purposes and cause no direct harm to their hosts ( Reynoldson, 1950 , 1951 , 1955 , 1956 ).…”

Section: Introductionmentioning

confidence: 99%

Nuclear and Mitochondrial SSU rRNA Genes Reveal Hidden Diversity of Haptophrya Endosymbionts in Freshwater Planarians and Challenge Their Traditional Classification in Astomatia

2022

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Like many other aquatic animals, freshwater planarians have also become partners of symbiotic ciliates from the class Oligohymenophorea. In the present study, we explored the hidden diversity and addressed the questionable systematic position of mouthless obligatory gut endosymbionts of freshwater planarians, using the nuclear and mitochondrial SSU rRNA genes. Although all isolated ciliates morphologically corresponded to a single species, molecular analyses suggested the existence of three genetically distinct entities: Haptophrya planariarum, Haptophrya dugesiarum nov. spec., and Haptophrya schmidtearum nov. spec. The two former species share the same planarian host, which indicates a speciation model involving one duplication event without host switching. Such a diversification pattern was recognized also in astome ciliates inhabiting megascolecid and glossoscolecid earthworms. The present multi-gene phylogenies along with the secondary structure of the mitochondrial 16S rRNA molecule, however, challenge the traditional classification of Haptophrya within the subclass Astomatia. Haptophrya very likely evolved from an orphan scuticociliate lineage by the loss of oral apparatus and by the transformation of the thigmotactic field into an adhesive sucker. Since astomy evolved multiple times independently within the Oligohymenophorea, the loss of cell mouth cannot be used as a sole argument for the assignment of Haptophrya to the Astomatia anymore.

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Section: Introductionmentioning

confidence: 99%

Nuclear and Mitochondrial SSU rRNA Genes Reveal Hidden Diversity of Haptophrya Endosymbionts in Freshwater Planarians and Challenge Their Traditional Classification in Astomatia

2022

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“…Finally, ciliates are ectoparasitic, and they can affect host movement and damage epithelium (Bowen and Ryder 1994). Planarian epithelium is immensely important since it produces mucus that enables gliding, and also likely provides a range of antimicrobial substances for a first line of defence.…”

Section: Discussionmentioning

confidence: 99%

Synergism between mutational meltdown and Red Queen in parthenogenetic biotypes of the freshwater planarian Schmidtea polychroa

Bruvo¹,

Schulenburg²,

Storhas³

et al. 2007

Oikos

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Do parasites and accumulation of deleterious mutations act synergistically in balancing the costs of sex? We addressed this possibility in the freshwater planarian flatworm Schmidtea polychroa . Sexual and parthenogenetic forms of this species sometimes coexist but show no ecological separation. Previous studies indicate that in a mixed sexual/ parthenogenetic population in Lago di Caldonazzo (N. Italy) parthenogens get more frequently infected with parasites. At the same time, they suffer from higher embryo mortality, which has been interpreted as a sign of accumulation of deleterious mutations. In the present study, we test whether these two factors are correlated, by focusing on the differences among the clonal lineages of a predominantly parthenogenetic subpopulation. Our results suggest that, for two out of three parasite types found, the infections are positively associated with the indirect measure of host mutation load.

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The Ecology of Freshwater Planarians

Vila‐Farré

Rink

2018

Methods in Molecular Biology

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Planarians are on the rise as a model system for regeneration and stem cell dynamics. Almost in parallel the interest in planarian field biology has declined. Besides representing an independent research discipline in its own right, understanding of the natural habitat is also directly relevant to optimizing culture conditions in the laboratory. Moreover, the current laboratory models are but few of hundreds of planarian species worldwide. Their adaptation to a wide range of ecological niches has resulted in a fascinating diversity of regenerative abilities, body size, reproduction strategies, and life expectancy, to name just a few. With the currently ongoing establishment of large planarian species collections, such phenotypic diversity becomes accessible to comparative mechanistic analysis in the laboratory. Overall, we hope that this chapter inspires an integral view of the planarian model system that not only includes the molecular and cellular processes under investigation but also the evolutionary forces that shaped them in the first place.

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Urceolaria mitra (von Seib) Epizoic on Polycelis tenuis (IJIMA) an SEM Study.

Cited by 6 publications

References 11 publications

Nuclear and Mitochondrial SSU rRNA Genes Reveal Hidden Diversity of Haptophrya Endosymbionts in Freshwater Planarians and Challenge Their Traditional Classification in Astomatia

Nuclear and Mitochondrial SSU rRNA Genes Reveal Hidden Diversity of Haptophrya Endosymbionts in Freshwater Planarians and Challenge Their Traditional Classification in Astomatia

Synergism between mutational meltdown and Red Queen in parthenogenetic biotypes of the freshwater planarian Schmidtea polychroa

The Ecology of Freshwater Planarians

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