scholarly journals Descriptive skeletal anatomy of Blommersia transmarina (Amphibia: Anura: Mantellidae) from the Comoro Islands

2019 ◽  
Vol 89 (1) ◽  
pp. 14-73 ◽  
Author(s):  
Javier H. Santos-Santos ◽  
Mireia Guinovart-Castán ◽  
David R. Vieites
Keyword(s):  
Phenotypic Variation ◽  
Morphological Analysis ◽  
Vomeronasal Organ ◽  
Species Dispersal ◽  
Geographic Ranges ◽  
Novel Structure ◽  
Internal Structures ◽  
The Indian Ocean ◽  
Non Destructive ◽  
Comoro Islands

Mantellid frogs present an extensive adaptive radiation endemic to Madagascar and Comoros, being the subfamily Mantellinae the most morphologically and ecologically diverse. The Mantellinae present key innovative evolutionary traits linked to their unique reproductive behavior, including the presence of femoral glands and a derived vomeronasal organ. In addition, previous studies pointed to size differentiation in playing an important role in species’ dispersal capacities and shaping of their geographic ranges. Despite the high phenotypic variation observed in this clade, to date an exhaustive morphological analysis of their anatomy has still not been performed, much less in relation to internal structures. Here, we present a comprehensive skeletal description of a mantellid species, Blommersia transmarina, from the island of Mayotte in the Indian Ocean, which has potentially undergone a process of moderate gigantism compared to other Blommersia species. We describe its intraspecific skeletal variation utilizing non-destructive volume renderings from μCT-scans, and characterize the presence of sexual dimorphism and size covariation in skeletal structures. Notably, we found numerous signs of hyperossification, a novel structure for mantellids: the clavicular process, and the presence of several appendicular sesamoids. Our findings suggest that skeletal phenotypic variation in this genus may be linked to biomechanical function for reproduction and locomotion.

Age and architecture of the largest African Baobabs from Mayotte, France

2020 ◽  
Author(s):  
Adrian Patrut ◽  
Roxana Patrut ◽  
Laszlo Rakosy ◽  
Karl von Reden
Keyword(s):  
Life Cycle ◽  
Radiocarbon Dating ◽  
Cluster Structure ◽  
Radiocarbon Date ◽  
General State ◽  
Adansonia Digitata ◽  
Open Ring ◽  
The Indian Ocean ◽  
Ring Shaped Structure ◽  
Comoro Islands

The volcanic Comoro Islands, located in the Indian Ocean in between mainland Africa and Madagascar, host several thousand African baobabs (Adansonia digitata). Most of them are found in Mayotte, which currently belongs to France, as an overseas department. We report the investigation of the largest two baobabs of Mayotte, the Big baobab of Musical Plage and the largest baobab of Plage N’Gouja. The Big baobab of Musical Plage exhibits a cluster structure and consists of 5 fused stems, out of which 4 are common stems and one is a false stem. The baobab of Plage N’Gouja has an open ring-shaped structure and consists of 7 partially fused stems, out of which 3 stems are large and old, while 4 are young. Several wood samples were collected from both baobabs and analyzed via radiocarbon dating. The oldest dated sample from the baobab of Musical Plage has a radiocarbon date of 275 ± 25 BP, which corresponds to a calibrated calendar age of 365 ± 15 yr. On its turn, the oldest sample from Plage N’Gouja has a radiocarbon date of 231 ± 20 BP, which translates into a calibrated age of 265 ± 15 yr. These results indicate that the Big baobab of Musical Plage is around 420 years old, while the baobab of Plage N’Gouja has an age close to 330 years. In present, both baobabs are in a general state of deterioration with many broken or damaged branches, and the Baobab of Plage N’Gouja has several missing stems. These observations suggest that the two baobabs are in decline and, most likely, close to the end of their life cycle.

scholarly journals Synchrotron radiation X-ray tomographic microscopy (SRXTM) of brachiopod shell interiors for taxonomy: Preliminary report

2010 ◽  
pp. 109-117 ◽  
Author(s):  
Neda Motchurova-Dekova ◽  
David Harper
Keyword(s):  
Synchrotron Radiation ◽  
Three Dimensional ◽  
X Rays ◽  
X Ray ◽  
Fine Grained ◽  
Internal Structures ◽  
Efficient Alternative ◽  
Micro Tomography ◽  
Light Beams ◽  
Non Destructive

Synchrotron radiation X-ray tomographic microscopy (SRXTM) is a non-destructive technique for the investigation and visualization of the internal features of solid opaque objects, which allows reconstruction of a complete three-dimensional image of internal structures by recording of the differences in the effects on the passage of waves of energy reacting with those structures. Contrary to X-rays, produced in a conventional X-ray tube, the intense synchrotron light beams are sharply focused like a laser beam. We report encouraging results from the use of SRXTM for purely taxonomic purposes in brachiopods: an attempt to find a non-destructive and more efficient alternative to serial sectioning and several other methods of dissection together with the non-destructive method of X-ray computerised micro-tomography. Two brachiopod samples were investigated using SRXTM. In ?Rhynchonella? flustracea it was possible to visualise the 3D shape of the crura and dental plates. In Terebratulina imbricata it was possible to reveal the form of the brachidium. It is encouraging that we have obtained such promising results using SRXTM with our very first two fortuitous samples, which had respectively fine-grained limestone and marl as infilling sediment, in contrast to the discouraging results communicated to us by some colleagues who have tested specimens with such infillings using X-ray micro-tomography. In future the holotypes, rare museum specimens or delicate Recent material may be preferentially subjected to this mode of analysis.

scholarly journals Three new cryptic species of the lamprey genus Lampetra Bonnaterre, 1788 (Petromyzontiformes: Petromyzontidae) from the Iberian Peninsula

2013 ◽  
Vol 82 (1) ◽  
pp. 37-53 ◽  
Author(s):  
Catarina S. Mateus ◽  
M. Judite Alves ◽  
Bernardo R. Quintella ◽  
Pedro R. Almeida
Keyword(s):  
New Species ◽  
Iberian Peninsula ◽  
Cryptic Species ◽  
Dna Markers ◽  
Morphological Analysis ◽  
Taxonomic Status ◽  
Geographic Ranges ◽  
Three New Species ◽  
Evolutionary Lineages ◽  
Small Tributary

The Iberian Peninsula is a repository for biodiversity, presenting high levels of endemism in both plants and animals. In this peninsular region, brook lampreys confined to small, isolated river basins evolved in allopatry giving rise to evolutionary lineages, as revealed by mitochondrial DNA markers. For a better understanding of the taxonomic status and relationships of Iberian populations of the genus Lampetra, we combined previous data from genetics and morphological analysis (assessed here), and describe three new species of the lamprey genus Lampetra Bonnaterre, 1788 in Portugal. In this region L. planeri actually represent a complex of cryptic species, each having smaller geographic ranges than L. planeri, and consequently, greater vulnerability to extinction. The description of Lampetra alavariensis sp. nov. is based on 36 specimens collected on Ribeira de Mangas, a tributary of river Esmoriz, in Northern Portugal. Lampetra auremensis sp. nov. is described on the basis of 31 specimens collected on Ribeira do Olival, a small tributary of river Nabão (Tagus basin). Finally, Lampetra lusitanica sp. nov. is described based on 38 specimens from Ribeira da Marateca, Sado river basin, the southernmost distribution of the genus Lampetra. The recognition of these new species will contribute to the conservation of these already imperilled taxa and will help prevent the extinction of three important evolutionary lineages.

scholarly journals Method of Multi-Angle Transmission Radiowave Tomography of Dielectric Objects

2020 ◽  
Vol 10 (9) ◽  
pp. 3270
Author(s):  
Dmitry Sukhanov ◽  
Kseniya Zavyalova
Keyword(s):  
Refractive Index ◽  
Time Delay ◽  
Homogeneous Medium ◽  
Projection Algorithm ◽  
Propagation Time ◽  
Destructive Testing ◽  
Internal Structures ◽  
Diffraction Effects ◽  
Dielectric Objects ◽  
Non Destructive

A method for solving the inverse problem for reconstructing the spatial distribution of dielectric permittivity from the results of multi-angle transmission broadband radiosounding is proposed. The method is based on inverse wave propagation. The average refractive index of the medium along the wave trajectory is calculated by comparing the results of the calculation of the time delay of the inverse signal in the entire sounding region and the forward propagation time in a homogeneous medium. This method takes into account diffraction effects in solving a direct problem, which allows one to obtain a resolution in the order of a wavelength. The combination of time delays obtained at different probing angles allows the restoration of the distribution of the refractive index in the medium. The paper presents the results of the numerical simulation of this method. The novelty of the proposed approach compared to the conventional back-projection algorithm is that ray approximation is not applied. Instead of the absorption coefficient (used in X-ray tomography), a time delay is considered, which is restored in the entire probed region. The developed method can be widely used in radiowave tomography or microwave tomography for remote non-destructive testing, diagnostics for the internal structures of inhomogeneous media and the restoration of the shapes of opaque objects based on multisensor sensing.

scholarly journals Age and architecture of the largest African Baobabs from Mayotte, France

2020 ◽  
Vol 1 (1) ◽  
pp. 33-47 ◽  
Author(s):  
Adrian Patrut ◽  
Roxana T. Patrut ◽  
Laszlo Rakosy ◽  
Karl F. Von Reden
Keyword(s):  
Radiocarbon Dating ◽  
Cluster Structure ◽  
Radiocarbon Date ◽  
General State ◽  
Adansonia Digitata ◽  
Open Ring ◽  
The Indian Ocean ◽  
Paleoclimate Reconstructions ◽  
Ring Shaped Structure ◽  
Comoro Islands

The volcanic Comoro Islands, located in the Indian Ocean in between mainland Africa and Madagascar, host several thousand African baobabs (Adansonia digitata). Most of them are found in Mayotte, which currently belongs to France, as an overseas department. Baobabs constitute a reliable archive for climate change and millennial specimens were recently used as proxies for paleoclimate reconstructions in southern Africa. We report the investigation of the largest two baobabs of Mayotte, the Big baobab of Musical Plage and the largest baobab of Plage N’Gouja. The Big baobab of Musical Plage exhibits a cluster structure and consists of 5 fused stems, out of which 4 are common stems and one is a false stem. The baobab of Plage N’Gouja has an open ring-shaped structure and consists of 7 partially fused stems, out of which 3 stems are large and old, while 4 are young. Several wood samples were collected from both baobabs and analyzed via radiocarbon dating. The oldest dated sample from the baobab of Musical Plage has a radiocarbon date of 275 ± 25 BP, which corresponds to a calibrated calendar age of 365 ± 15 yr. On its turn, the oldest sample from Plage N’Gouja has a radiocarbon date of 231 ± 20 BP, corresponding to a calibrated age of 265 ± 15 yr. These results indicate that the Big baobab of Musical Plage is around 420 years old, while the baobab of Plage N’Gouja has an age close to 330 years. In present, both baobabs are in a general state of deterioration with many broken or damaged branches, and the Baobab of Plage N’Gouja has several missing stems. These observations suggest that the two baobabs are in decline and, most likely, close to the end of their life cycle.

The Use of Comorian Documents

1985 ◽  
Vol 12 ◽  
pp. 349-355
Author(s):  
Martin Ottenheimer
Keyword(s):  
Indian Ocean ◽  
Fifteenth Century ◽  
Western Indian Ocean ◽  
Maritime Trade ◽  
Volcanic Origin ◽  
Historical Significance ◽  
Long Period ◽  
The Indian Ocean ◽  
Oral Information ◽  
Comoro Islands

The Comorian archipelago is located at the northern end of the Mozambique channel in the western Indian Ocean. Of volcanic origin, the archipelago consists of four major islands and several smaller ones which, for many centuries, have been the sites of ports for ships from Asia, Africa, and Europe. They played an especially prominent role in the networks of maritime trade in the Indian Ocean during the fifteenth century and were involved in the maritime trade much earlier. As one would expect of people involved in trade over a long period of time, Comorians have been keepers of records. Thus, the Comoro Islands have become a rich source of both written and oral documents.Some of the numerous documents that have been discovered on the islands have served as the basis of the published histories of the Comoros. Others have been published themsleves and all have provided valuable information about life in the islands. Many documents, however, still remain unpublished. I have had the opportunity to collect numerous documents over the nearly twenty years that I have been gathering information about the Comoro Islands, and this collection continues to grow today. When I am not in the islands, Comorians send or bring documents to me in Kansas which I copy or record before returning them to their owners. During my trips to the islands I have taped oral information, photographed data of historical significance, hand-copied documents, and have been given or lent rare publications.

scholarly journals Morphological Analysis for Neuron-Like Cells in the Vomeronasal Organ of Human Fetuses at the Middle of Gestation

2015 ◽  
Vol 299 (1) ◽  
pp. 88-97 ◽  
Author(s):  
Shigeru Takami ◽  
Maiko Yukimatsu ◽  
George Matsumura ◽  
Sawa Horie ◽  
Fumiaki Nishiyama
Keyword(s):  
Morphological Analysis ◽  
Vomeronasal Organ ◽  
Human Fetuses
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