Search results for " marine"
showing 10 items of 1338 documents
Analysis of the trophic role of Mediterranean seagrasses in marine coastal ecosystems: a review
2009
Abstract Seagrasses form high-productivity coastal ecosystems, providing habitats for many organisms, including species of commercial value. They play a significant role as a direct food source for herbivores and also enter detrital food webs. In this review, the trophic ecology of Mediterranean seagrass ecosystems is revised, with major emphasis on Posidonia oceanica, the most extensively studied seagrass. The major topics are the role of herbivory and detritus, the contribution to littoral fish production, exportation to other ecosystems and the seagrass role as a vector of anthropogenic nutrients into food webs. Topics are discussed by analysing both conventional knowledge and new insigh…
Sea level and climate forcing of the Sr isotope composition of late Miocene Mediterranean marine basins
2014
Sr isotope records from marginal marine basins track the mixing between seawater and local continental runoff, potentially recording the effects of sea level, tectonic, and climate forcing in marine fossils and sediments. Our 110 new Sr-87/Sr-86 analyses on oyster and foraminifera samples from six late Miocene stratigraphic sections in southern Turkey, Crete, and Sicily show that Sr-87/Sr-86 fell below global seawater values in the basins several million years before the Messinian Salinity Crisis, coinciding with tectonic uplift and basin shallowing. 87Sr/86Sr from more centrally located basins (away from the Mediterranean coast) drop below global seawater values only during the Messinian S…
Stable C and N isotope concentration in several tissues of the loggerhead sea turtle Caretta caretta from the western Mediterranean and dietary impli…
2007
CONCENTRACIÓN DE ISÓTOPOS ESTABLES DE C Y N EN VARIOS TEJIDOS DE LA TORTUGA BOBA CARETTA CARETTA DEL MEDITERRÁNEO OCCIDENTAL E IMPLICACIONES SOBRE LA DIETA. – La concentración isotópica de escudos del caparazón, piel, músculo y sangre de tortuga boba (Caretta caretta) fueron analizados para investigar el patrón de variación entre tejidos y para evaluar la posición de esta especie en las redes tróficas de la cuenca Argelina. La piel presentaba valores más altos de δ13C que el músculo o los escudos del caparazón y éstos presentaban valores más altos que la sangre. En cambio, el músculo presentaba valores más altos de δ15N que la piel, ésta valores más altos que la sangre y ésta valores más al…
The end of the Messinian Salinity Crisis in the western Mediterranean: insights from the carbonate platforms of south-eastern Spain.
2010
International audience; How the Messinian Salinity Crisis (MSC) ended is still a matter of intense debate. The Terminal Carbonate Complex (TCC) is a late Messinian carbonate platform system that recorded western Mediterranean hydrological changes from the final stages of evaporite deposition till the advent of Lago-Mare fresh- to brackish water conditions at the very end of Messinian times. A multidisciplinary study has been carried out in three localities in south-eastern Spain to reconstruct the history of TCC platforms and elucidate their significance in the MSC. Overall, this study provides evidence that the TCC formed following a regional 4th order water level rise and fall concomitant…
Occurrence of two rare species from order Lampriformes: Crestfish Lophotus lacepede (Giorna, 1809) and scalloped ribbonfish Zu cristatus(Bonelli, 181…
2017
The bony fish Lophotus lacepede (Giorna, 1809) and Zu cristatus (Bonelli, 1819) are the two species rarely recorded within the Mediterranean basin, usually reported as accidentally captured in depth (mesopelagic) fishing operations. In the current work, we present the first record of L. lacepede and Z. cristatus in fishing catches from southwestern Tyrrhenian Sea. Moreover, in order to improve existent biological/ ecological knowledge, some bio-related aspects such as feeding aspect, sexual maturity and age estimate have been discussed.
Expression of one sponge Iroquois homeobox gene in primmorphs from Suberites domuncula during canal formation
2003
SUMMARY Sponges (Porifera) represent the evolutionary oldest multicellular animals. They are provided with the basic molecules involved in cell–cell and cell–matrix interactions. We report here the isolation and characterization of a complementary DNA from the sponge Suberites domuncula coding for the sponge homeobox gene, SUBDOIRX-a. The deduced polypeptide with a predicted Mr of 44,375 possesses the highly conserved Iroquois-homeodomain. We applied in situ hybridization to localize Iroquois in the sponge. The expression of this gene is highest in cells adjacent to the canals of the sponge in the medulla region. To study the expression of Iroquois during development, the in vitro primmorph…
Zoology and Animal Ecology: Abstract book : 25 January 2023, Nature House University of Latvia, Riga, Latvia
2023
The Zoology and Animal Ecology section of the conference covers a broad range of topics, ranging from the distribution of animal species and the different aspects of species' interactions with the environment to animal genetics and physiology, including behaviour, conservation and other topics where study objects are animals.
Analysis of manganese deposits from the Alps
2011
Deposits with unusually high Mn contents sampled at Monte Mangart in the Julian Alps include organic-rich marlstone and black shale with interbedded manganoan and siliceous limestone, which were deposited during the early Toarcian Oceanic Anoxic Event. Mn enrichment during that period has been related to global sea-level change coincident with increasing subsidence rate. The formation of Fe-Mn nodules, marking a hardground at the base of the Monte Mangart section, seems to be triggered by release of Mn from remote hydrothermal vents into a region of relatively elevated submarine topography where oxidizing conditions prevailed. However, very high Mn contents in carbonate phases above the har…
Marinesco-Sjögren syndrome caused by a new SIL1 frameshift mutation
2015
no abstract available
Mn, Fe, Zn and As speciation in a fast-growing ferromanganese marine nodule
2004
The speciation of Mn, Fe, As and Zn in a fast-growing (0.02mm/yr), shallow-marine ferromanganese nodule has been examined by micro X-ray fluorescence, micro X-ray diffraction, and micro X-ray absorption spectroscopy. This nodule exhibits alternating Fe-rich and Mn-rich layers reflecting redox variations in water chemistry. Fe occurs as two-line ferrihydrite. The As is strictly associated with Fe and is mostly pentavalent, with an environment similar to that of As sorbed on or coprecipitated with synthetic ferrihydrite. The Mn is in the form of turbostratic birnessite with ~;10 percent trivalent manganese in the layers and probably ~;8 percent corner-sharing metal octahedra in the interlayer…