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Le Touquet – Paris-Plage, France

Geerinckx T.,Ghent University | Herrel A.,MNHN | Adriaens D.,Ghent University
Journal of Experimental Zoology Part A: Ecological Genetics and Physiology

Suckermouth armored catfishes (Loricariidae) use their suckermouth for inspiration, feeding, and attachment to substrates. The sucker consists of a pre-valvular cavity, formed by a modified lip disc, and is separated from the larger post-valvular buccal cavity by a muscular oral valve. The combination of respiration and suction attachment seems paradoxal, as a properly functioning suction device would need a sucker without leakage (yet inspiration must occur via the sucker), and continuous subambient pressure in the sucker cavity (even during expiratory mouth floor elevation). In the loricariid Pterygoplichthys disjunctivus, the anatomy of the suckermouth structures was examined, and a kinematic analysis was performed to acquire insights into how respiration and attachment are combined. High-speed external and X-ray recordings show that suckermouth attachment influences respiratory parameters such as decreasing excursion amplitudes of mouth floor elements, and the way water enters the mouth via furrows in the lip disc. Respiration, however, continues during attachment and is not blocked. Our data show that the muscular oral valve actively separates the post-valvular buccal cavity from the pre-valvular sucker cavity. Volume changes of this pre-valvular cavity are opposite to those of the post-valvular cavity and assure sucker function even during expiration. These volume changes are caused by movements of the lower lip, the lower jaws, and the oral valve. The lateral inflow furrow openings, controlled by the maxillary barbels, can occur unilaterally. Morphological and kinematic data also show that the opercle is anatomically and functionally decoupled from the gill opening. © 2010 Wiley-Liss, Inc., A Wiley Company. Source

Humbert J.F.,French National Institute for Agricultural Research | Quiblier C.,MNHN | Quiblier C.,University Paris Diderot | Gugger M.,Institute Pasteur Paris | Gugger M.,French National Center for Scientific Research
Analytical and Bioanalytical Chemistry

Harmful phytoplankton species are a growing problem in freshwater and marine ecosystems, because of their ability to synthesize toxins that threaten both animal and human health. The monitoring of these microorganisms has so far been based on conventional methods, mainly involving the microscopic counting and identification of cells, and using analytical and bioanalytical methods to identify and quantify the toxins. However, the increasing number of microbial sequences in the GeneBank database and the development of new tools in the last 15 years nowadays enables the use of molecular methods for detection and quantification of harmful phytoplankton species and their toxins. These methods provide species-level identification of the microorganisms of interest, and their early detection in the environment by PCR techniques. Moreover, real time PCR can be used to quantify the cells of interest, and in some cases to evaluate the proportion of toxin-producing and non-toxin-producing genotypes in a population. Recently, microarray technologies have also been used to achieve simultaneous detection and semi-quantification of harmful species in environmental samples. These methods look very promising, but so far their use remains limited to research. The need for validation for routine use and the cost of these methods still hamper their use in monitoring programs. © 2010 Springer-Verlag. Source

In the past 50 years, the turbot is referred to either as Scophthalmus maximus (Linnaeus, 1758) or Psetta maxima (Linnaeus, 1758) in the literature. Norman (1931) had argued that the valid name for the turbot was Scophthalmus maximus. However, his recommendation was never universally accepted, and today the confusing situation exists where two generic names are still being used for this species. We address this issue by analysing findings from recently published works on the anatomy, molecular and morphological phylogenetic systematics, and ecology of scophthalmid fishes. The preponderance of evidence supports the strong recommendation to use Scophthalmus as the valid generic name for the turbot. Acceptance of this generic name conveys the best information available concerning the systematic relationships of this species, and also serves to simplify the nomenclature of scophthalmid flatfishes in publications on systematics, fisheries and aquaculture, fishery statistics, ichthyofaunal and field guides for the general public, and in various legal and conservation-related documents. This paper reinforces the conclusions of Chanet (2003) with more arguments. Source

Ruff C.B.,Johns Hopkins University | Puymerail L.,French National Center for Scientific Research | Macchiarelli R.,MNHN | Macchiarelli R.,University of Poitiers | And 2 more authors.
Journal of Human Evolution

The original hominin femur (Femur I) and calotte discovered at Trinil, Java by Eugene Dubois in 1891/1892 played a key role in the early history of human paleontology by purportedly demonstrating the contemporaneity of archaic cranial form with modern human erect (bipedal) posture. On this basis, both specimens were subsequently assigned to Pithecanthropus erectus, later transferred to Homo erectus. However, chronological and phylogenetic links between the two have been questioned from the beginning. Four additional hominin partial femora (Femora II-V) from Trinil were subsequently described but have played a relatively minor part in evolutionary scenarios. Here we present the results of a new analysis of structural and density characteristics of the Trinil femora obtained using computed tomography. Trinil Femur I shows none of the characteristics typical of early Homo femora from elsewhere in Asia or Africa, including a relatively long neck, increased mediolateral bending rigidity of themid-proximal shaft, or a low position of minimum mediolateral breath on the shaft. In contrast, Femora II-V all demonstrate features that are more consistent with this pattern. In addition, material density distributions within the specimens imply more recent and less complete fossilization of Femur I than Femora II-V. Thus, it is very likely that Trinil Femur I derives from a much more recent time period than the calotte, while the less famous and less complete Femora II-V may represent H.erectus at Trinil. The morphological variation within the Trinil femora can be attributed to broader changes in pelvic morphology occurring within the Homo lineage between the Early and late Middle Pleistocene. © 2015 Published by Elsevier Ltd. Source

David R.,MNHN
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference

This abstract presents new results on the structure and function of vestibular part of the inner ear of vertebrates with special emphasis on human behavior. First we summarize a mathematical analysis of motion of the endolymphatic fluid, justifying known approximated formulas for the cupula functioning based on a set of anatomical parameters. Some of these parameters can be estimated from the bony labyrinth, some others cannot be. We present original data issued from synchrotron microtomography (S μ CT) of five tetrapod species, allowing to compare bony and membranous labyrinths. We derive several simple and robust empirical laws connecting membranous parameters and bony parameters. Then, using published results on human labyrinths (Bradshaw et al. 2009), we deduce functional consequences for the human labyrinths. For instance we show that, contrarily to current belief, the kinematic sensitivity for yaw is larger than for pitch and roll. Source

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