Search results for "Arbacia"
showing 10 items of 30 documents
Functional traits of two co-occurring sea urchins across a barren/forest patch system
2013
Abstract Temperate rocky reefs may occur in two alternative states (coralline barrens and erect algal forests), whose formation and maintenance are often determined by sea urchin grazing. The two sea urchin species Paracentrotus lividus and Arbacia lixula are considered to play a similar ecological role despite their differing morphological traits and diets. The patchy mosaic areas of Ustica Island, Italy, offer an ideal environment in which to study differences in the performance of P. lividus and A. lixula in barren versus forest states. Results show that the two sea urchin species differ in diet, trophic position, grazing adaptation, movement ability and fitness in both barren and forest…
Arbacia
2013
Sea urchins of the genus Arbacia are widely distributed throughout the world occurring in tropical, temperate and sub-Antartic zones. In the past, Arbacia has been the object of intensive investigations in cell biology and biochemistry of fertilization and early development. Renewed interest in the genus Arbacia arose mainly due to its ecological role and its unusual geographic distribution. All the six species of Arbacia are omnivorous with a strong tendency to carnivory. Recent manipulative and morpho-functional studies demonstrated that Arbacia species play an important role in the ecology of rocky reefs. They maintain barren areas by scraping either fleshy and encrusting algae and anima…
Successo di fecondazione di Arbacia lixula: limitazione da sperma e longevità dei gameti
2011
Mining extraction in the ocean depths: a baseline to understand and reduce acoustic impact on biodiversity.
2020
[ES] A lo largo de la historia, el hombre ha explotado los recursos minerales de la tierra para su supervivencia y desarrollo tecnológico sin un equilibrio con su regeneración. Dado el crecimiento de la población mundial y la reducción de recursos, el hombre comenzó a buscar nuevos depósitos que se encontraron en la década de 1960 en las profundidades de los océanos. Con estos, la humanidad empezò a pensar en extraer los minerales de estos depósitos y esto llevò al nacimiento de Deep Sea Mining (DSM). Las consecuencias de las actividades mineras en las profundidades del mar no se conocen realmente y los efectos pueden ser diferentes: contaminación acústica, contaminación lumínica, contamina…
Spine and test skeletal matrices of the Mediterranean sea urchinArbacia lixula- a comparative characterization of their sugar signature
2015
15 pages; International audience; Calcified structures of sea urchins are biocomposite materials that comprise a minor fraction of organic macromolecules, such as proteins, glycoproteins and polysaccharides. These macromolecules are thought to collectively regulate mineral deposition during the process of calcification. When occluded, they modify the properties of the mineral. In the present study, the organic matrices (both soluble and insoluble in acetic acid) of spines and tests from the Mediterranean black sea urchin Arbacia lixula were extracted and characterized, in order to determine whether they exhibit similar biochemical signatures. Bulk characterizations were performed by mono-di…
SOME COMPARATIVE REMARKS ON THE TRANSIENT CHANGE IN LACTIC ACID CONTENT IN SEA URCHIN EGGS FOLLOWING FERTILIZATION.
1964
Abstract During the first few minutes following fertilization a transient increase in the concentration of lactic acid occurs in the eggs of Arbacia lixula , whereas no change at all is observed in the eggs of Paracentrotus liuidus . In the eggs of Psammechinus miliaris there is a transient decrease, soon followed by a recovery so that the level of the unfertilized egg is again reached.
Effects of temperature rising and ocean acidification on reproductive success in the sea urchin Arbacia lixula (L.)
2011
Population structure of the sea urchins Paracentrotus lividus and Arbacia lixula across a depth gradient
2006
Sea urchins are considered to have a paramount role in structuring rocky shallow communities. Under certain conditions, grazing by sea-urchins has been reported to produce a shift from macroalgae-dominated communities to barren habitat dominated by encrusting algae. However, this process is not recorded at all depths. The effect of depth on the structure of the sea-urchin populations may be thus a key feature to understand the origin and maintenance of the barren habitat within certain depths. In the present study, the structure of Paracentrotus lividus (Lam.) and Arbacia lixula (L.) populations are analyzed across a depth gradient in the Ustica Island MPA (NW Mediterranean), where the barr…