Publications by authors named "Sarah Samadi"

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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  • * New mitogenomes from various deep-sea gastropods were analyzed, revealing novel genetic data and relationships among different gastropod groups, including significant discoveries about the Cocculiniformia and vetigastropod superfamilies.
  • * Findings indicate that the deep-sea gastropods evolved from shallow-water ancestors, with insights into habitat transitions and the evolution of chemosynthetic behavior in certain lineages.
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Rhodopsin mediates an essential step in image capture and is tightly associated with visual adaptations of aquatic organisms, especially species that live in dim light environments (e.g., the deep sea).

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Urban structures like marinas are dominant features of our coasts, often hotspots for invasive species. The processes that govern the distribution of invasive species within and between marinas are not well understood. We therefore investigated the impacts of local-scale variability within and between marinas, analysing fouling communities at two zones (inner and outer) within three close marinas in accordance with pollutants recorded in the water and sediment.

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We assembled the mitogenome of the Bythograeid crab , using long-range amplification of the mitochondrial genome. The mitogenome is 15,521 base pair long (33.8% A, 21.

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  • The Red-whiskered bulbul is a successful invasive species with notable morphological differences linked to its environment on Reunion Island, indicating a rapid capacity for local adaptation.
  • Researchers investigated the invasion histories of the bulbul populations on Reunion Island, Mauritius, and Oahu to understand the connection between these histories and the birds' morphological changes.
  • Findings revealed that while the invasive populations share a similar origin, their morphology has diverged, highlighting the influence of both neutral evolution and environmental adaptation on the species across different islands.
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DNA barcoding approaches are used to describe biodiversity by analysing specimens or environmental samples in taxonomic, phylogenetic and ecological studies. While sharing data among these disciplines would be highly valuable, this remains difficult because of contradictory requirements. The properties making a DNA barcode efficient for specimen identification or species delimitation are hardly reconcilable with those required for a powerful analysis of degraded DNA from environmental samples.

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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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This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.

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Bathymodiolinae are giant mussels that were discovered at hydrothermal vents and harboring chemosynthetic symbionts. Due to their close phylogenetic relationship with seep species and tiny mussels from organic substrates, it was hypothesized that they gradually evolved from shallow to deeper environments, and specialized in decaying organic remains, then in seeps, and finally colonized deep-sea vents. Here, we present a multigene phylogeny that reveals that most of the genera are polyphyletic and/or paraphyletic.

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The Coral Sea, located at the southwestern rim of the Pacific Ocean, is the only tropical marginal sea where human impacts remain relatively minor. Patterns and processes identified within the region have global relevance as a baseline for understanding impacts in more disturbed tropical locations. Despite 70 years of documented research, the Coral Sea has been relatively neglected, with a slower rate of increase in publications over the past 20 years than total marine research globally.

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  • The text discusses the need for practical methods to define and evaluate species flocks, particularly in the Antarctic shelf's benthic fauna.
  • The authors apply five criteria to assess various taxa, focusing on historical criteria of endemicity, monophyly, and species richness due to practical limitations.
  • They identify nine definitive species flocks, suggest eight additional "core flocks" for further ecological study, and challenge the idea that marine species flocks are uncommon.
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The giant bathymodioline mussels from vents have been studied as models to understand the adaptation of organisms to deep-sea chemosynthetic environments. These mussels are closely related to minute mussels associated to organic remains decaying on the deep-sea floor. Whereas biological data accumulate for the giant mussels, the small mussels remain poorly studied.

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  • - The family Chrysogorgiidae, which contains octocorals found primarily in deep waters, is highlighted for studying biodiversity and evolutionary processes in the deep sea, supported by the first detailed phylogenetic analysis of its generas.
  • - Researchers used mitochondrial and nuclear genetic markers to analyze phylogenetic relationships among 10 of the 14 Chrysogorgiidae genera, revealing that the family is polyphyletic, with some genera being more closely related to other families rather than to each other.
  • - The study found that strictly deep-sea Chrysogorgiidae genera diversified in their deep-water environments, while some species previously identified in shallower depths suggest a possible emergence from these areas, indicating complex patterns of origin
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Controversy regarding the species problem has been going on for many decades and no consensus has ever been reached about what a "species" really is and how best to define the concept. De Queiroz (1998) introduced a distinction between two aspects of this problem: on the one hand, the definition proper, and on the other, the criteria allowing biologists to recognize species in practice. This distinction is a first step on the way toward a solution of the problem.

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Bathymodiolinae mussels have been used as a biological model to better understand the evolutionary origin of faunas associated with deep-sea hydrothermal vents and cold seeps. Most studies to date, however, have sampled with a strong bias towards vent and seep species, mainly because of a lack of knowledge of closely related species from organic falls. Here we reassess the species diversity of deep-sea mussels using two genes and a large taxon sample from the South-Western Pacific.

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A new genus of a deep-sea ascomycete with one new species, Alisea longicolla, is described based on analyses of 18S and 28S rDNA sequences and morphological characters. A. longicolla was found together with Oceanitis scuticella, on small twigs and sugar cane debris trawled from the bottom of the Pacific Ocean off Vanuatu Islands.

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Article Synopsis
  • Bathymodiolinae mussels thrive in extreme environments like deep-sea hydrothermal vents and cold seeps, relying on chemosynthetic bacteria in their gills for nutrition in the absence of sunlight.
  • Over the past thirty years, research has expanded our understanding of these mussel-bacteria symbioses, with ongoing discoveries about their diversity and evolutionary roles.
  • The article highlights new findings about small mussels found on sunken wood in the Philippines, emphasizing the need for further study of these less-researched species compared to those in more well-studied environments.
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Bathymodiolin mussels occur at hydrothermal vents and cold seeps, where they thrive thanks to symbiotic associations with chemotrophic bacteria. Closely related genera Idas and Adipicola are associated with organic falls, ecosystems that have been suggested as potential evolutionary 'stepping stones' in the colonization of deeper and more sulphide-rich environments. Such a scenario should result from specializations to given environments from species with larger ecological niches.

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We re-assess the value of morphological specific descriptors within the spring-snail genus Bythinella by sequencing mitochondrial COI and nuclear ITS1 gene fragments. Taxonomic coverage represents 16 nominal species sampled among 35 populations from France. Application of monophyly and cohesive haplotype networks as criteria to delineate species allow us to identify 10 mitochondrial species-level lineages, all but one of which are recovered by ITS1.

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Molecular data were used to study the diversity of mytilids associated with sunken-woods sampled in the Solomon Islands and discuss the 'wooden steps to deep-sea vent' hypothesis proposed by Distel et al. First, COI data used in a barcoding approach confirm the presence of four distinct species. Analyses of the 18S rDNA and COI dataset then confirmed that these sunken-wood mytilids belonged to a monophyletic group including all species from deep-sea reducing environments.

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  • Understanding the reasons for pest eradication failure helps improve future methods and protocols.
  • The study analyzed genetic differences in ship rat populations on four islets in Martinique to determine whether rats persisted after an eradication attempt or were reinvaded.
  • Findings revealed that one island had a surviving population with little genetic change, while another showed signs of reinvasion with increased genetic diversity, suggesting a need for improved eradication procedures and ongoing monitoring.
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