33 research outputs found

    A New and aberrant species of <i>Dugesia</i> (Platyhelminthes, Tricladida, Dugesiidae) from Madagascar

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    In this paper we report a new species of Dugesia of the family Dugesiidae from Madagascar, representing the fourth species of freshwater planarian known from this global biodiversity hotspot. In some respects the new species is aberrant, when compared with its congeners, being characterized by a head with smoothly rounded auricles, a peculiar course of the oviducts, including the presence of a common posterior extension, and by the asymmetrical openings of the vasa deferentia at about halfway along the seminal vesicle. Further, it is characterized by a ventral course of the ejaculatory duct with a terminal opening, very long spermiducal vesicles and unstalked cocoons. Its diploid chromosome complement with 18 chromosomes represents an uncommon feature among fissiparous species of Dugesia

    Sponges architecture by colour: new insights into the fibres morphogenesis, skeletal spatial layout and morpho-anatomical traits of a marine horny sponge species (Porifera)

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    This paper focuses on the skeletal architecture and morphotraits of the Mediterranean horny sponge Sarcotragus spinosulus (Demospongiae, Keratosa, Dictyoceratida, Irciniidae). This special endoskeletal system consists of a dense, variably complex connective architecture, which extends throughout the entire sponge body and is embedded in an abundant jelly-like extracellular matrix (ECM). To investigate the topographic arrangement and micro-morphotraits of these connective structures in detail and by colour, also during morphogenetic processes, histology techniques using light microscopy are essential. New information is provided on the coordinated morphogenetic processes that characterize the growth and assembly of collagenic prototype structures in the matrix of fibrous skeletal elements and drive skeleton remodelling. Our results also highlight some novelties and some remarkable peculiarities of fibrous, filamentous and fibrillar components at the levels of both composition and structure. The morphofunctional significance of skeletal architecture is suggested in the background of the anatomical complexity of S. spinosulus

    Planarians of temporary waters (Platyhelminthes tricladida)

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    Freshwater planarians are fragile animals susceptible to desiccation and high temperature and characterized by a poor dispersal power requiring contiguous freshwaters to survive and disperse. They are indeed excellent biogeographic models. However, some species of Planariidae (genera Phagocata and Hymanella) and Dugesiidae (genus Spathula) are known inhabiting temporary waters particularly from the Nearctic, Palaearctic and Australasian regions

    How to survive and persist in ephemeral water bodies?: the case of sponges (Porifera: Spongillina)

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    Ephemeral water bodies are subjected to unforeseeable and extreme fluctuations of environmental conditions constraining biodiversity values. Although data are fragmentary and scattered in the literature sponges are known to be able to colonize temporary/intermittent water bodies

    The oldest birotule-bearing freshwater sponges from the Upper Cretaceous–lower Paleocene Deccan volcanic-associated sediments of India

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    A new fossil occurrence of freshwater sponges (Porifera: Demospongiae) is reported from the Deccan volcanic associated Naskal intertrappean locality, deposited in an interval of <100 kyr across the Cretaceous/Paleogene (K/Pg) boundary. This is the oldest record of siliceous fossil birotule spicules (gemmuloscleres) belonging to asexual resting stages typical of the order Spongillida. The analysis supports the ascription of these fossils to the family Palaeospongillidae. The diagnosis and description of Longibirotula Pronzato and Manconi gen. nov. and its type species Longibirotula antiqua Manconi and Samant sp. nov. from the Naskal intertrappean is based on skeletal and gemmular spicular morphotraits. The findings have provided evidence of the presence of diversified groups of freshwater sponges during the Late Cretaceous on the Indian subcontinent and Gondwanaland. From the biogeographic context, the findings track the evolutionary trends of the oldest continental sponges in the Asian and Australasian/Insular Pacific regions

    Three dispersal routes out of Africa: A puzzling biogeographical history in freshwater planarians

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    Aim Freshwater planarians may have a wide geographical range despite their assumed low vagility. Found across four continents, Dugesia may have either an ancient origin on a large palaeo landmass, followed by colonisation in different regions before continental fragmentation, or a more recent origin and subsequent transoceanic dispersal. We seek to resolve between these two hypotheses. Location Africa, Eurasia and Australasia. Taxon Genus Dugesia (Platyhelminthes: Tricladida: Dugesiidae). Methods We used data from the sequencing of six gene fragments and comprehensive taxonomic sampling of Dugesia from across its distribution range to reconstruct the phylogeny of this genus using maximum likelihood and bayesian inference methods. We conducted two phylogenetic dating analyses using Platyhelminthes fossils and palaeogeological events. Basing on the time-calibrated molecular phylogenetic framework we evaluated the contribution of vicariance and dispersal to the biogeographical evolution of Dugesia. By reconstructing the ancestral areas and present-day potential distribution using BioGeoBEARS and niche modelling, we elucidated the biogeographical history of the genus. Results The present-day distribution of Dugesia is a result of different vicariance and dispersal events. However, we also found evidence of transoceanic dispersal. Consistent with previous hypotheses, Dugesia dates to the Upper Jurassic in the Afro-Malagasy Gondwana region. We unveiled a novel biogeographical scenario for the genus, involving multiple events of colonisation in Eurasia from continental Africa via at least three dispersal routes. Main conclusions Dugesia is an ancient genus having reached its present distribution through a complex history of dispersal and vicariant events following its origin in southern Gondwana. Despite the low vagility of Dugesia, we found evidence of their overseas dispersal

    80 years of research on planarians (Platyhelminthes, Tricladida) from Sardinia, Italy: an annotated checklist

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    Stocchino, Giacinta Angela (2018): 80 years of research on planarians (Platyhelminthes, Tricladida) from Sardinia, Italy: an annotated checklist. Zootaxa 4532 (4): 539-552, DOI: https://doi.org/10.11646/zootaxa.4532.4.

    Dugesia hepta Pala, Casu & Vacca 1981

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    &lt;i&gt;Dugesia hepta&lt;/i&gt; Pala, Casu &amp; Vacca, 1981 &lt;p&gt; &lt;i&gt;Dugesia hepta&lt;/i&gt; is a Sardinian endemic species restricted only to four hydrographic basins in the northwestern part of the island (Pala &lt;i&gt;et al&lt;/i&gt;., 1981; Stocchino &lt;i&gt;et al&lt;/i&gt;., 2005) (Fig. 1). The species is characterized by a peculiar chromosome number (2n = 14; n = 7), from which derives its specific epithet, which is unique within the Palaearctic Region. This chromosomal pattern is known only for &lt;i&gt;Dugesia ryukyuensis&lt;/i&gt; Kawakatsu, Oki, Tamura &amp; Sugino, 1976, and &lt;i&gt;D. batuensis&lt;/i&gt; Ball, 1970, both from eastern Asia (Ball, 1970; Kawakatsu &lt;i&gt;et al&lt;/i&gt;., 1976). &lt;i&gt;Dugesia hepta&lt;/i&gt; is also morphologically well distinguishable because of a peculiar dorsal ejaculatory duct with a lateral opening and a ventro-lateral penial fold. Among &lt;i&gt;Dugesia&lt;/i&gt; species this dorsal course of the ejaculatory duct character is shared by only one other species viz. &lt;i&gt;D. superioris&lt;/i&gt; Stocchino &amp; Sluys, 2013 from Lake Ohrid in Albania (Stocchino &lt;i&gt;et al&lt;/i&gt;., 2013b, 2017c). &lt;i&gt;Dugesia hepta&lt;/i&gt; populations are exclusively sexual with a life cycle comparable to that of other European dugesiids, such as &lt;i&gt;D. ilvana&lt;/i&gt; Lepori, 1948 from Elba Island and &lt;i&gt;D. gonocephala&lt;/i&gt; (Dug&egrave;s, 1830) from Central Europe (cf. Stocchino &amp; Manconi, 2013). A recent origin of &lt;i&gt;D. hepta&lt;/i&gt; from &lt;i&gt;D. benazzii&lt;/i&gt; was suggested by molecular analysis (Lazaro &lt;i&gt;et al&lt;/i&gt;., 2009). This hypothesis is also supported by the coexistence of the two species at many localities in all of the Sardinian hydrographic basins inhabited by &lt;i&gt;D. hepta&lt;/i&gt;.&lt;/p&gt;Published as part of &lt;i&gt;Stocchino, Giacinta Angela, 2018, 80 years of research on planarians (Platyhelminthes, Tricladida) from Sardinia, Italy: an annotated checklist, pp. 539-552 in Zootaxa 4532 (4)&lt;/i&gt; on page 540, DOI: 10.11646/zootaxa.4532.4.5, &lt;a href="http://zenodo.org/record/2615649"&gt;http://zenodo.org/record/2615649&lt;/a&gt

    Microplaninae Pantin 1953

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    Subfamily Microplaninae Pantin, 1953 The first record of an autochthonous land planarian from Sardinia was reported by Stocchino et al. (2008) from the karstic Su Guanu Cave in the northwestern part of the island. Specimens were found during three sampling campaigns in a hydropetric habitat, just after the wet season. Presence of terrestrial planarians in a cave habitat may be considered as accidental, probably being the result of passive dispersion occasioned by water flowing through the limestone cracks from surface ground layers to the interior of the cave. Survival of land planarians in this peculiar habitat is ensured, at least for some time, by presence in the cave of suitable preys such as oligochaetes, insect larvae and gastropods. On the basis of some diagnostic morphological characters specimens were assigned to the subfamily Microplaninae. However, absence of fully sexually developed individuals prevented a detailed assessment of their taxonomic status (Stocchino et al., 2008).Published as part of Stocchino, Giacinta Angela, 2018, 80 years of research on planarians (Platyhelminthes, Tricladida) from Sardinia, Italy: an annotated checklist, pp. 539-552 in Zootaxa 4532 (4) on page 547, DOI: 10.11646/zootaxa.4532.4.5, http://zenodo.org/record/261564

    Dugesia sicula Lepori 1948

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    Dugesia sicula Lepori, 1948 Dugesia sicula was first reported for Sardinia on the basis of fissiparous populations, in which a certain percentage of individuals underwent a sexualization process, from 12 Sardinian localities, including 2 small nearby islets (spring and wells on the Tavolara Island Protected Area and watercourses on the S. Antioco Island) (Pala et al., 1995) (Fig. 1). After several years other fissiparous populations were found in two other watercourses, one in the northwestern Asinara Island National Park (Rio d’Auteri reservoir) (Stocchino, 2003) and another in southeastern Sardinia (Fiume Quirra) (M. Pala, pers. comm.) (Fig. 1). All Sardinian populations showed a coastal distribution with a high degree of tolerance to variations in environmental factors, especially temperature and watercourses hydrological regime e.g. temporary water (Pala et al., 1995; G.A. Stocchino, pers. obs.). Dugesia sicula has a pan-Mediterranean geographic range where it is mostly represented by fissiparous populations with only a few sexual populations being present in Mallorca, Algeria, Tunisia and Israel. Two mixed populations, including both sexual and fissiparous individuals, were reported from Sicily (Stocchino & Manconi 2013 and references therein). A recent reassessment of the taxonomic status of D. biblica Benazzi & Banchetti, 1973 from Israel and Turkey, based on morphological and molecular studies, considered this species to be a junior synonym of D. sicula (Solà et al., 2015). As for karyology, numerous studies confirmed a diploid condition for sexual populations with a chromosome complement of 2n = 18; n = 9, and a triploid condition for fissiparous populations with a chromosome complement of 3n = 27; n = 9 + 1-5 B-chromosomes (see Stocchino et al., 2012 and references therein). Among Dugesia species, the haploid complement of nine chromosomes of D. sicula is shared with only five other species: D. maghrebiana Stocchino et al., 2009, from North Africa; D. arabica Harrath & Sluys, 2013 from Yemen; D. aethiopica Stocchino et al., 2002 and D. afromontana Stocchino & Sluys, 2012 from the Afrotropical region; D. bifida Stocchino & Sluys, 2014 from Madagascar (Stocchino et al., 2002, 2004, 2009, 2012, 2014; Harrath et al., 2013). Although D. sicula is extremely widespread, a molecular analyses on many fissiparous populations from its entire distributional range revealed a remarkable pattern of low interpopulation genetic variability, which was interpreted as the result of recent anthropochore colonizations after triploidization of sexual diploid populations (Lazaro et al., 2009).Published as part of Stocchino, Giacinta Angela, 2018, 80 years of research on planarians (Platyhelminthes, Tricladida) from Sardinia, Italy: an annotated checklist, pp. 539-552 in Zootaxa 4532 (4) on page 541, DOI: 10.11646/zootaxa.4532.4.5, http://zenodo.org/record/261564
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