Search results for "Mediterranean sea"
showing 10 items of 876 documents
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…
The size and shape of shells used by hermit crabs: A multivariate analysis of Clibanarius erythropus
2009
Shell attributes such as weight and shape affect the reproduction, growth, predator avoidance and behaviour of several hermit crab species. Although the importance of these attributes has been extensively investigated, it is still difficult to assess the relative role of size and shape. Multivariate techniques allow concise and efficient quantitative analysis of these multidimensional properties, and this paper aims to understand their role in determining patterns of hermit crab shell use. To this end, a multivariate approach based on a combination of size-unconstrained (shape) PCA and RDA ordination was used to model the biometrics of southern Mediterranean Clibanarius erythropus populatio…
Health effects of mercury ingested through consumption of seafood
1995
It is known world-wide literature that seafood consumption is the main source of mercury intake in people not occupationally exposed. Several studies on the presence of mercury in sea water, sediment and fish and its effects on human health have been carried out in many countries in the Mediterranean area such as Greece, Italy and Jugoslavia. Few data have been published on Sicilian coastal population, consumers of high amounts of fish and on seawater status as the starting point of alimentary chains involving marine food. This study was carried out in July 1991 and July 1992 to determine total mercury and methylmercury levels in selected populations of the coast of Sicily: fishermen in a l…
Megabenthos Underwater Video (MUV): a new device to evaluate species distribution in hard-to-reach marine areas
2021
A device, called Megabenthos Underwater Video (MUV), was designed and built for the counting and the size estimate of benthic organisms in hard-to-reach areas. Since 2014 Cassiopea andromeda, an invasive alien jellyfish in the Mediterranean Sea with benthic behavior, colonized a recreational harbor (Cala) of Palermo with a stable population. Studying the species distribution in this area with classical methods (such as visual census, ROV, etc.) was not applicable due to the large presence of obstacles (ropes, anchor cables, boats) and to dive difficulties in these types of area. The MUV was tested from 2017 to 2018 for the study of the spatial-temporal distribution of C. andromeda in the Ca…
Seasonal population dynamics of Zeuxapta seriolae (Monogenea: Heteraxinidae) parasitising Seriola dumerili (Carangidae) in the Western Mediterranean.
2013
We examined the seasonal and yearly population dynamics of the monogenean pathogen Zeuxapta seriolae on juvenile fish from wild populations of Seriola dumerili. The study is based on bimonthly monitoring between April, 2005 and April, 2007 off Majorca, and newly obtained monogenean population data for juvenile fish from three additional localities in the Western Mediterranean (off Alicante, Corsica and Sardinia). We documented the highest intensities and abundances of Z. seriolae, with mean abundance values similar to or higher than those reported in the single case of wild fish mortalities reported to date. There was a recurrent pattern of seasonal change in infection with Z. seriolae in t…
Assessment of the Sabellaria alveolata reefs’ structural features along the Southern coast of Sicily (Strait of Sicily, Mediterranean Sea)
2022
The honeycomb worm Sabellaria alveolata is a gregarious tube-dwelling polychaete that builds remarkable biogenic reefs in marine coastal waters. Sabellaria alveolata reefs are considered valuable marine habitats requiring protection measures for their conservation, as they play a key role in the functioning of coastal ecosystems. Sabellarid reefs are extensively developed along the Atlantic coasts of Europe and reported for the Mediterranean Sea and the Italian coasts, where large reefs have been recorded in several localities. Fragmentary information is available on their health status, Sabellaria reefs thus being listed as “Data Deficient” in the Red List of Marine Habitats. To fill this …
DISTRIBUTION PATTERNS OF TWO LABRID SPECIES IN THE WESTERN MEDITERRANEAN: IS WATER WARMING AFFECTING THEIR ECOLOGICAL INTERACTIONS?
2009
Climate warming should favor ‘warm water’ species over ‘cold water’ species at the same site. Regional warming in the Western Mediterranean has allowed the documented northward expansion of southern marine species. Conversely, very little is known on the response of cold loving species to temperature variations. We propose to work with two common coastal fishes: the rainbow wrasse Coris julis and the ornate wrasse Thalassoma pavo, with the general objective to exploring patterns of distribution and their potential to interact under warming conditions. Large scale quantitative observations revealed: (1) opposing trends in abundance along latitudinal (35o − 45oN) and depth gradients (0-36m), …
A review of methods to assess connectivity and dispersal between fish populations in the Mediterranean Sea
2013
Fish populations are linked to each other via dispersal of individuals as eggs, larvae, juveniles or adults. The understanding of this process, known as connectivity, has a pivotal role for the management of overexploited fish stocks and the development of accurate conservation strategies. Knowledge on connectivity and fish movements is considered fundamental toward the correct design of marine protected area (MPA) networks for the achievement of the benefits of protection. Connectivity patterns are still largely unknown worldwide. A general lack of knowledge is particularly evident for the Mediterranean Sea where few studies dealing with this topic have been carried out and some methods, c…
On the occurrence of the silverstripe blaasop Lagocephalus sceleratus (Gmelin, 1789) along the Libyan coast
2012
Five individuals of Lagocephalus sceleratus were caught by trammel and gill nets off Ain Al Ghazala, Libya (approximately 32°09'N − 23°15'E) between 15 and 25 m depth in September 2010. Our findings represent the first record of this toxic species from Libya and provide further evidence of its occurrence along North African coasts.
Vertical distribution of two sympatric labrid fishes in the Western Mediterranean and Eastern Atlantic rocky subtidal: local shore topography does ma…
2011
Changes in the shore topography (e.g. slope) occur at a scale of hundreds of meters in several locations in the Lusitanian and the Mediterranean Sea provinces. We tested whether differences in the bottom inclination might affect the vertical distribution patterns of two sympatric coastal labrid fishes, the rainbow wrasse Coris julis and the ornate wrasse Thalassoma pavo. Visual censuses were used to determine the distribution and abundance of these labrid species in high (‡30 ) and low (£3 ) slope rocky substrates covered by brown macroalgae and at two different depths (shallow, 4–7 m, and deep 14–20 m). Pectoral fin aspect ratio was used as an estimate of swimming performance to potentiall…