6 research outputs found

    The stenoendemic cave-dwelling planarians (Platyhelminthes, Tricladida) of the Italian Alps and Apennines: Conservation issues

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    Despite being a fundamental component of biodiversity, several highly diverse taxa of aquatic invertebrates are still poorly known and poorly considered in protection programs. This is the case especially of several invertebrate species that inhabit groundwater. In this environment, invertebrates play significant roles in ecosystem services closely connected to the usefulness of these systems for human welfare and survival. The groundwater biodiversity of continental Italy is largely unknown and its importance is neglected in national and regional legislation. One of the most poorly studied groups of Italian groundwater fauna are planarians (Platyhelminthes, Tricladida). Most known species are endemic to small, single karst areas or a single cave, their geographic range never having been investigated in detail after the original description. The aims of this study are i) to provide the first conservation assessment of cave-dwelling planarians in the Italian Alps and Apennines, whose status is at present Not Evaluated in IUCN categories and ii) to evaluate which environmental constraints, including potential threats, possibly affect the occurrence of the species within different cave systems. Our results suggest that most of the cave-dwelling planarian species of continental Italy are threatened by water pollution and habitat destruction/alteration; moreover, datasets underline that there is a considerable conservation issue concerning stenoendemic planarians that may involve other cave-dwelling invertebrates with narrow geographic ranges. Generally, the underground habitat of most surveyed species appears to be deeply compromised and changed since the first species description

    A new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from the Afromontane forest in South Africa, with an overview of freshwater planarians from the African continent

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    A new species of the genus Dugesia from the Amatola Mountains in the Eastern Province of South Africa is described, including a karyological account and notes on its life cycle and reproductive modes. The new species differs from its congeners in a unique combination of morphological characters of the copulatory apparatus, in particular the central course of the ejaculatory duct with its terminal opening at the tip of the penis papilla, the elongated seminal vesicle, the asymmetrical openings of the oviducts into the bursal canal, and the openings of vasa deferentia at about halfway along the seminal vesicle. In addition, an overview is provided of all freshwater triclads reported from the African continent including karyological information and notes on reproductive modes

    Molecular barcoding and phylogeography of sexual and asexual freshwater planarians of the genus Dugesia in the Western Mediterranean (Platyhelminthes, Tricladida, Dugesiidae)

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    Planarians of the genus Dugesia have a worldwide distribution with high species diversity in the Mediterranean area. In this area, populations with a triploid karyotype that reproduce by fissiparity are exceptionally frequent, outnumbering the sexual populations. This situation poses interesting questions, such as the age of these asexual lineages, whether they all belong to the same species or whether the triploidization event is recurrent, and what factors (climatic, geographical, historical...) explain the prevalence of these asexual forms. However, asexual populations cannot be assigned to a species due to the lack of copulatory apparatus - the main structure used in species identification. In this study, we have developed a DNA barcoding method, based on COI and ITS-1 sequences, which allows the assignment of the fissiparous forms to sexual species. At the same time, phylogenetic analysis from species of the western Mediterranean have unveiled the presence of species with highly differentiated populations alongside species with a wide distribution and almost no genetic variation. The roles of habitat instability, dispersal capacity and human activities are briefly discussed

    African planarians: Morphology and karyology of Dugesia maghrebiana sp. n. (Platyhelminthes, Tricladida) from Tunisia

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    Extensive surveys were made of Tunisian freshwaters, yielding freshwater planarians at only one locality in southeastern Tunisia, representing a new species. Dugesia maghrebiana sp. n. is characterized by the presence of the following features: ventral course of the ejaculatory duct, terminal opening of the ejaculatory duct, double diaphragm, symmetrical openings of the oviducts into the bursal canal, and by a typical condition of mixoploidy with a double aneuploidic chromosome complement. The taxonomic position of the new species is discussed in relation to other African and Mediterranean species
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