Publications by authors named "Magalie Castelin"
Based on molecular and conchological features, a new genus, Bouchetaria, is proposed for the Cypraeidae species Nesiocypraea aenigma Lorenz 2002. Molecular analysis of cox1 and 16S genes places Bouchetaria within a monophyletic group-composed of the genera Propustularia, Nesiocypraea, Ipsa, Perisserosa, Cryptocypraea, and Nucleolaria-appearing as the sister group to all other living Cypraeidae. This group corresponds to the Erosariinae (sensu Lorenz & Hubert, 1993).
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- Tropical coral reefs, covering only 0.1% of the Earth's surface, are home to immense marine biodiversity and provide essential services, but face threats from global issues like climate change and local challenges such as chemical pollution.
- This study systematically reviewed experiments on chemical toxicity to reef-building corals to create useful data for ecological risk assessment, determining toxicity thresholds and comparing them to regulatory safety levels for marine life.
- The research leveraged a comprehensive database of ecotoxicological studies to ensure rigorous evaluation of the impacts of pollutants on corals, assessing the quality of the studies and aiming to create actionable knowledge for ecosystem management.
Based on the specimens collected during three deep-sea cruises, and deposited at the Muséum National d'Histoire Naturelle (MNHN) in Paris, we analysed the diversity of benthic communities within the EEZ of French Polynesia. The literature and the MNHN database allowed us to inventory 471 species of invertebrates, among which 169 were newly described. We mainly found data for Mollusca, Crustacea, Brachiopoda and Crinoidea.
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- - The study focused on freshwater shrimp specimens from the Caridina nilotica complex collected in the South Western Indian Ocean, involving both genetic (16S mitochondrial analysis) and morphological comparisons.
- - Findings indicated that what was previously identified as various species of the C. nilotica complex is actually the valid species C. natalensis, first described in 1908.
- - The research also includes a re-description of C. natalensis and comparisons with similar species that are commonly confused with it, such as C. brachydactyla, C. brevidactyla, C. gracilipes, and C. longirostris.
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- The Tonnoidea is a group of around 360 species of large predatory sea snails that secrete sulfuric acid to prey on invertebrates like echinoderms.
- Recent genetic analyses of approximately 80 species confirmed that Tonnoidea is monophyletic, meaning all members share a common ancestor, while also revealing unexpected relationships among different genera.
- The study led to a revised classification of Tonnoidea into nine families, highlighting several genera that may need reclassification due to being either mixed (para- or polyphyletic) or potentially synonyms of one another.
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- Molecular genetic methods are crucial in conservation biology because they help identify hidden biodiversity, particularly in freshwater ecosystems where species like crayfishes may show significant genetic differences that aren't visible morphologically.
- This study presents the first comprehensive phylogenetic analysis of the crayfish genus Pacifastacus, including both problematic invasive species (like Pacifastacus leniusculus) and endangered species (like Pacifastacus fortis).
- By analyzing 83 crayfish samples and utilizing various genetic markers, the research determined that Pacifastacus is a monophyletic group and identified numerous distinct species within it, highlighting the urgent conservation needs for these species in western North America.
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- - Connectivity among populations is crucial for understanding their dynamics and evolution, and accurately defining evolutionary units (like populations and species) is essential for ecology and conservation biology.
- - There is a disconnect between taxonomists and molecular ecologists, especially in marine environments, where many species remain unidentified and cryptic species are common, leading to biased estimates of population connectivity.
- - The study proposes ways to improve species delimitation by treating it as testable hypotheses and suggests better sampling strategies to enhance the accuracy of connectivity studies in relation to taxonomic work.
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- Digeneans and cestodes are diverse groups of flatworms that can negatively affect human health, fisheries, agriculture, and wildlife management.
- Traditional DNA barcoding methods often fail due to high variability in priming sites among flatworm species, making it challenging to design suitable primers.
- Researchers developed new degenerate primers that successfully amplified the COI barcode region from all tested specimens, significantly improving species identification and contributing to filling gaps in public DNA databases.
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- Devising a reliable way to define new species in highly diverse groups is challenging in evolutionary biology, requiring an integrative approach due to complex speciation processes.
- A two-step method combining Automated Barcode Gap Discovery (ABGD) and Klee diagrams was applied to the Terebridae snail family to improve speed and accuracy in suggesting species boundaries.
- The study found 17 potential new snail species using this approach, highlighting ABGD and Klee diagrams as effective tools for identifying species in species-rich environments.
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- - Both historical and contemporary factors influence how aquatic species populations are connected, particularly in the Indo-Pacific region, with specific focus on amphidromous gobies.
- - Research shows that geographical barriers, like the shallow Sunda shelf and open oceans, create breaks in genetic connectivity across different goby populations, even for species that can disperse widely.
- - Genetic analysis reveals significant isolation in one goby species (Sicyopus zosterophorum) due to the Torres Strait barrier, while another species (Smilosicyopus fehlmanni) shows different population patterns, leading to hypotheses about their distinct genetic structures.
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- - The Sicydiinae subfamily is crucial for the diversity of fish in tropical island river systems, found mainly in regions like the Indo-Pacific, Caribbean, and West Africa, and is noted for its unique life cycle of spawning in freshwater, drifting to the sea as larvae, and returning to rivers to grow and reproduce—this behavior is termed amphidromy.
- - Researchers examined the genetic makeup of 59 Sicydiinae fish specimens using 5 genetic markers and found that most genera were monophyletic, except for Sicydium, which was determined to be paraphyletic across five major clades identified, including clades with Stiphodon and Sicyopterus.
- - The study challenges previous theories about how
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- A new genus called Elephantis is introduced for the species Caridina natalensis, previously known only from a single male specimen in South Africa.
- Recent surveys in Madagascar have found numerous specimens, allowing for a detailed morphological description that highlights unique features distinguishing it from other Caridina species.
- Molecular analysis of mitochondrial DNA from these specimens supports its classification as a distinct group and can aid in future studies of freshwater shrimps' phylogeny.
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- * The Kuhliidae family, comprising 12 tropical island fish species, shows well-defined evolutionary patterns for migratory behavior, with catadromous species being the most ancient.
- * The study suggests that limited resources in tropical marine environments and the transient nature of freshwater habitats contribute to the evolution of migratory patterns in Kuhlia species, highlighting its significance for understanding adaptation in changing ecosystems.