517 research outputs found

    Molecular detection of parasites (Trematoda, Digenea: Bucephalidae and Monorchiidae) in the European flat oyster Ostrea edulis (Mollusca: Bivalvia)

    Get PDF
    Members of the globally distributed bivalve family Ostreidae (oysters) have a significant role in marine ecosystems and include species of high economic importance. In this work, we report the occurrence of digenean parasites of the families Bucephalidae (Prosorhynchoides sp.) and Monorchiidae (Postmonorchis sp.) in Mediterranean native populations of Ostrea edulis (but not in the introduced Magallana gigas). Molecular detection was based on DNA sequencing of the ribosomal intergenic spacer 2 (ITS2) marker. The importance of detecting the presence of overlooked digenean parasites in Mediterranean oysters is discussed. © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

    The southernmost record of Felimida elegantula (Philippi, 1844) (Gastropoda: Nudibranchia)

    Get PDF
    The southernmost record of the Mediterranean nudibranch Felimida elegantula (Philippi, 1844) is reported here. A single specimen, with a colour pattern that hampered an easy morphological identification, was collected at the Kerkennah Islands (Tunisia). DNA-barcoding analysis (with the cytochrome c oxidase subunit I genetic marker) unambiguously confirmed its identification, and radular and anatomical features conformed with those previously described. With this record, the chromatic polymorphism of F. elegantula is demonstrated to be extremely large and the known range of the species is extended to the African coast of Tunisia

    Phenotypic diversity of Thuridilla hopei (Verany, 1853) (Gastropoda Heterobranchia Sacoglossa). A DNA-barcoding approach

    Get PDF
    The sacoglossan Thuridilla hopei (Verany, 1853) shows highly diverse chromatic patterns. Based on the morphological examination of specimens from different Mediterranean localities, we have observed that in spite of this great variability in colours of T. hopei, two major chromatic morphotypes are related to bathymetry. Specimens from deeper water exhibit blue darker and more uniform patterns than individuals from shallower water, which show a more variable, dashed and spotted arrangement of light blue, yellow, orange, white and black pigmentation. A molecular genetic analysis using the mitochondrial COI and 16S rDNA markers has confirmed that all these extremely different chromatic morphotypes belong to a single specific entity, i.e. T. hopei, a sacoglossan with a wide distribution, from Macaronesia in the Atlantic, to the easternmost Mediterranean Sea

    Sympatric sibling species: The case of Caloria elegans and Facelina quatrefagesi (Gastropoda: Nudibranchia)

    Get PDF
    The aeolid nudibranch Caloria elegans (Facelinidae) is quite common in the Mediterranean Sea and eastern Atlantic Ocean and is easily recognized by the presence of a typical black spot at the apical portion of its cerata. Facelina quatrefagesi (Facelinidae) was long considered as a synonym of C. elegans until recently, when it was re-evaluated as a valid species based mainly on rhinophore morphology. In order to definitively assess the status of these aeolid taxa, we employed an integrative taxonomy approach using the nuclear H3 and the two mitochondrial cytochrome oxidase subunit I and 16S markers. The molecular analyses clearly showed that, although morphologically closely related to C. elegans, F. quatrefagesi is a valid species

    Mediterranean spreading of the bicolor purse oyster, Isognomon bicolor, and the chicken trigger, Malleus sp., vs. the Lessepsian prejudice

    Get PDF
    The introduction rate of alien species in the Mediterranean Sea is rapidly growing, and their taxonomical identification is increasingly challenging. This uncertain identification often leads to an incorrect estimation of the number of alien species, their route of introduction, and their potential negative effects. This is particularly true for some bivalves, which are characterized by high variation in their shells, resulting in uncertain morphological identification. This is the case for two alien bivalves, i.e., an Isognomonidae and a Malleidae species, both characterized by confused historical colonization records in the Mediterranean Sea, misidentifications, and controversial and changing nomenclatures that have insofar negatively affected our knowledge on their geographical distributions. In this respect, molecular approaches provide a strategy that is especially useful when traditional taxonomy fails, and DNA barcoding is a powerful and well-known tool to obtain reliable identifications through efficient molecular markers. In this work, we used the 16S rRNA marker to assess the preliminary identification of Isognomon sp. and Malleus sp. specimens from different localities in the Southern Mediterranean Sea. Bayesian inference (BI) and maximum likelihood (ML) methods were applied to test the monophyly of the phylogenetic linages and to clarify their taxonomic positions, allowing a complete overview of the colonization and spreading of these two alien bivalves in the Mediterranean Sea. In particular, the Isognomon sp. specimens were identified as the Atlantic I. bicolor, highlighting that previously suggested invasive migration patterns, (i.e., the Lessepsian migration), must be reconsidered with stronger critical attention in light of currently occurring global changes

    Inhibition of acetylpolyamine and spermine oxidases by the polyamine analogue chlorhexidine

    Get PDF
    ""Acetylpolyamine and spermine oxidases are involved in the catabolism of polyamines. The discovery of selective. inhibitors of these enzymes represents an important tool for the development of novel anti-neoplastic drugs. Here, a. comparative study on acetylpolyamine and spermine oxidases inhibition by the polyamine analogue chlorhexidine. is reported. Chlorhexidine is an antiseptic diamide, commonly used as a bactericidal and bacteriostatic agent.. Docking simulations indicate that chlorhexidine binding to these enzymes is compatible with the stereochemical. properties of both acetylpolyamine oxidase and spermine oxidase active sites. In fact, chlorhexidine is predicted. to establish several polar and hydrophobic interactions with the active site residues of both enzymes, with binding. energy values ranging from −7.6 to −10.6 kcal\\\/mol. In agreement with this hypothesis, inhibition studies indicate that. chlorhexidine behaves as a strong competitive inhibitor of both enzymes, values of Ki being 0.10 μM and 0.55 μM for. acetylpolyamine oxidase and spermine oxidase, respectively."

    SegICP: Integrated Deep Semantic Segmentation and Pose Estimation

    Full text link
    Recent robotic manipulation competitions have highlighted that sophisticated robots still struggle to achieve fast and reliable perception of task-relevant objects in complex, realistic scenarios. To improve these systems' perceptive speed and robustness, we present SegICP, a novel integrated solution to object recognition and pose estimation. SegICP couples convolutional neural networks and multi-hypothesis point cloud registration to achieve both robust pixel-wise semantic segmentation as well as accurate and real-time 6-DOF pose estimation for relevant objects. Our architecture achieves 1cm position error and <5^\circ$ angle error in real time without an initial seed. We evaluate and benchmark SegICP against an annotated dataset generated by motion capture.Comment: IROS camera-read

    First record of Calma gobioophaga Calado and Urgorri, 2002 (Gastropoda: Nudibranchia) in the Mediterranean Sea

    Get PDF
    Specimens of the nudibranch genus Calma were observed under stones at two Croatian localities while feeding on gobiid eggs. Some ambiguous morphological features compared with the original descriptions of the known species of the genus, C. glaucoides and C. gobioophaga, hampered an easy identification. Genetic data (COI and 16S sequences) confirmed the distinction between the two species of the genus Calma, and allowed to unambiguously identify the Croatian specimens as Calma gobioophaga. This is the first record of this species for the Mediterranean and extends remarkably its distribution range. Finally, the eggs fed by the Croatian specimens have been taxonomically identified by using the 12S rDNA marker as Gobius cobitis
    • …
    corecore