Search results for "feature"
showing 10 items of 4091 documents
Assessing vermetid reefs as indicators of past sea levels in the Mediterranean
2020
Abstract The endemic Mediterranean reef building vermetid gastropods Dendropoma petraeum complex (Dendropoma spp) and Vermetus triquetrus develop bio-constructions (rims) on rocky shorelines at about Mean Sea Level (MSL) and are therefore commonly used as relative sea-level (RSL) markers. In this study, we use elevations and age data of vermetid reefs to (1) re-assess the vertical uncertainties of these biological RSL indicators, and (2) evaluate the vertical growth rates along a Mediterranean east-west transect, in attempt to explain the differences found in both growth rates and uncertainties. In Israel, Differential Global Positioning System (DGPS) and laser measurements relative to the …
Contribution of planktonic and benthic food sources to the diet of the reef-forming vermetid gastropod Dendropoma petraeum in the western Mediterrane…
2012
Abstract In the Mediterranean Sea, the vermetid Dendropoma petraeum (Monterosato, 1884) forms highly biodiverse reefs that have received increasing attention in recent years although very little is known about the food habit of this species. The main goal of this study was to describe the trophic role of planktonic and benthic food sources for D. petraeum . Specimens from three morphological zones of the reef (inner edge, cuvette and outer edge) at two sites with different wave exposure along the north-western coast of Sicily (Italy; western Mediterranean) were compared for δ 13 C and δ 15 N. Isotopic determinations were also carried out on potential food sources identified in epilithon, re…
The cork oak in the Mountains of Palermo (Italy): ecological insights from the south-eastern edge of its distribution range
2020
Abstract: The uneven presence of the cork oak (Quercus suber L.) within its distribution range is not only determined by its climatic requirements but also by specific edaphic needs. Although most of the natural populations thrive in acidic soils deriving from metamorphic or volcanic rock outcrops, some cork oak populations are found growing in soils deriving from calcareous bedrock, which are considered less suitable. We carried out a multidisciplinary investigation at the south eastern edge of the Q. suber distribution range (Mountains of Palermo, NW Sicily), including soil, floristic, and vegetation surveys, aimed at: (i) assessing the native or introduced origin of some peculiar cork oa…
First Data on the Mysid Community in the “Stagnone di Marsala” (Western Sicily)
2001
First data on the spatial and temporal distribution of the mysid community in the “Stagnone di Marsala” (western Sicily) from January to December 1996 are reported. The assemblage consists mainly of five species which are common in the Mediterranean Sea: Diamysis bahirensis (55.2%), Siriella armata (18.6%), S. clausii (15.8%), Mysidopsis gibbosa (9.8%) and Mesopodospis slabberi (0.6%). Population structure is described for each species and the reproductive period inferred. A sharp increase in abundance occurred in the spring, while the minima occurred during autumn-winter. The D. bahirensis dominated from March to October and S. clausii in the winter. A large difference, which was mainly qu…
Hatching Success of Caretta caretta on a Mediterranean Volcanic Beach: Impacts from Environmental Parameters and Substrate Composition
2022
New data on the potential impact of environmental parameters and the mineralogical nature of the substrate on the hatching success of the loggerhead sea turtle Caretta caretta on a volcanic beach on Linosa Island in the central Mediterranean Sea are reported. During 2 years of investigation (2018-19), five nests were observed. The temperature and moisture of the nests were determined along with the grain size and mineralogical nature of the substrate. The temperature values of the nests recorded at depths of 5 and 35 cm showed an average temperature incubation of 32.2°C ± 1.4°C and 32.8°C ± 1.6°C, respectively, with peaks close to 37°C. The sedimentological analysis carried out on two cores…
First record of a representative of the subfamily Paradiaptominae (Copepoda Calanoida Diaptomidae) in Italy: Metadiaptomus chevreuxi (Guerne & Richar…
2005
Metadiaptomus chevreuxi (Guerne & Richard 1894), a diaptomid calanoid copepod belonging to the subfamily Paradiaptominae, has been found in two neighbouring temporary pools in the Egadi Archipelago (Sicily, southern Italy). This finding constitutes the first record of a representative of this subfamily in Italy and the second known European record for this species. M. chevreuxi, commonly found in the arid areas of Maghreb, has already been reported to occur in Mallorca Island (Balearic Archipelago, Spain), while it seems to be rare in the eastern quadrants of the Mediterranean basin. The characteristics of the new Italian site are briefly described and drawings of morphological details …
Unmanned aerial vehicle technology to assess the state of threatened biogenic formations: The vermetid reefs of mediterranean intertidal rocky coasts
2021
Abstract Vermetid bioconstructions are biogenic formations, built by sessile gastropod molluscs belonging to the family Vermetidae worldwide distributed, occurring in the intertidal and upper subtidal in the rocky shores. In the Mediterranean basin, they occur in complex and tridimensional structures that enhance the local biodiversity, allowing to qualify the structuring species as ecosystem engineers. Due to their ecological relevance and considerable extension along the coasts, we assessed their structural complexity using unmanned aerial vehicle (UAV) technology, as tool of littoral cartography analysis of these bioconstructions, and plaster hemispheres dissolution as a descriptor index…
The influence of light attenuation on the biogeomorphology of a marine karst cave: A case study of Puerto Princesa Underground River, Palawan, the Ph…
2015
Karst caves are unique biogeomorphological systems. Cave walls offer habitat for microorganisms which in-turn have a geomorphological role via their involvement in rock weathering, erosion and mineralisation. The attenuation of light with distance into caves is known to affect ecology, but the implications of this for biogeomorphological processes and forms have seldom been examined. Here we describe a semi-quantitative microscopy study comparing the extent, structure, and thickness of biocover and depth of endolithic penetration for samples of rock from the Puerto Princesa Underground River system in Palawan, the Philippines, which is a natural UNESCO World Heritage Site.\ud \ud Organic gr…
Crushing predation of the spiny star Marthasterias glacialis upon the sea urchin Paracentrotus lividus
2009
Literature data report that only fish predators are able to crush sea urchin tests in Mediterranean rocky reefs. This experimental study showed that the spiny star Marthasterias glacialis is able to break Paracentrotus lividus tests and that the breaking event is more likely to occur for small-sized sea urchins than for big ones. Our results show that the role of M. glacialis in regulating P. lividus population density can be important in specific locations. They may have important implications, moreover, for the use of tethering techniques aimed at identifying predator types of sea urchins.
The Messinian Salinity Crisis deposits in the Balearic Promontory: An undeformed analog of the MSC Sicilian basins??
2021
International audience; The Messinian Salinity Crisis (MSC) is a controversial geological event that influenced the Mediterranean Basin in the late Miocene leaving behind a widespread Salt Giant. Today, more than 90% of the Messinian evaporitic deposits are located offshore, buried below the Plio-Quaternary sediments and have thus been studied mainly by marine seismic reflection imaging. Onshore-offshore records’ comparisons and correlations should be considered a key approach to progress in our understanding of the MSC.This approach has however not been widely explored so far. Indeed, because of the erosion on the Messinian continental shelves and slopes during the MSC, only few places in …