Search results for "mediterranean sea."
showing 10 items of 830 documents
Protein differences among the Mediterranean species of the genus Spicara.
1996
Protein electrophoresis (PAGE) was used to study the three morphologically different species of Spicara (S. flexuosa, S. maena, S. smaris). Of the 28 enzymatic and additional myogenic loci, five monomorphic loci (LDH-1*, G6PD-1*, PGI-1* and two PMMs*) were species-specific markers of S. smaris with respect to S. flexuosa and S. maena. Four of the 28 enzymatic loci were polymorphic (EST-1*, GLDH*, PEPD*, PGI-2*). Discriminating genetic markers were not identified between S. flexuosa and S. maena. Genetic distance (D) as calculated by Nei’s index (1978), between S. smaris v. S. maena and S. flexuosa showed a value, respectively of D=0·137 and 0·141. Between S. flexuosa and S. maena the value …
Diet of Phycis blennoides (Gadidae) in Relation to Fish Size and Season in the Western Mediterranean (Spain)
2002
. Despite its commercial value, little is known about the feeding ecology of the greater forkbeard, Phycis blennoides (Brunnich 1768). The stomach contents of 2631 greater forkbeard were taken at monthly intervals off the coast of the Gulf of Valencia (western Mediterranean). They were examined in order to assess the diet and to determine the fish size- and season-related dietary variation of the species. Prey items were identified to the lowest taxonomic level possible. The basic food consisted of epibenthic species, mostly Decapoda, Mysidacea and Teleostei. A change in food composition based on fish size was observed and seasonal variation in diet was also recorded. The food overlap analy…
Calcareous nannofossil surface sediment assemblages from the SicilyChannel (central Mediterranean Sea): palaeoceanographic implications.
2008
Quantitative analysis of 67 calcareous nannofossil assemblages from surface sediments recovered in a wide area across the Sicily Channel has been carried out in order to improve the interpretation of palaeontological data based on this planktonic group in a key area for Mediterranean palaeoceanographic studies. The investigation focused on three case studies that demonstrate the high potentiality of such a combined approach, taking into account the recent distribution of taxa or groups of taxa on the sea floor and the palaeontological record. The distribution of reworked specimens over the northern Sicily Channel sea floor validates the role of southern Sicily as a source region for reworke…
Surface and deep water conditions in the Sicily channel (central Mediterranean) at the time of sapropel S5 deposition
2011
New centennial-scale data of benthic foraminifera assemblages and of stable isotopes of foraminifera shells from the Sicily Channel, representative of surface and bottom waters, over the interval between about 140 and 110 kyr BP, are presented. During this period anoxia developed on the eastern Mediterranean basin and sapropel S5 deposited. Although anoxic sediments have not been deposited in the Sicily Channel, this area is strategic to study the character of intermediate waters, whose chemical-physical properties strongly precondition the eastern Mediterranean deep water formation. So far, no data from these water masses have been obtained, apart from the isotopic composition of shells of…
Interacción entre el Monzón de África Occidental y el clima Mediterráneo en verano: Artículo de revisión
2014
Although in the framework of the global climate research the Mediterranean climate variability and the West African Monsoon (WAM) dynamics have been considered for a long time as “passive” systems, i.e., prone to the influence of large scale ocean and atmospheric variability, over the last decade many studies have been dedicated to the WAM-Mediterranean interaction and the active role of these climate systems has been highlighted. This article presents the WAM-Mediterranean teleconnection through an overview of the recent literature, describing the observational evidences and the dynamical mechanisms underlying this climate teleconnection. The influence of the Mediterranean Sea thermal anom…
Annual variation of parasite communities of deep-sea macrourid fishes from the western Mediterranean Sea and their relationship with fish diet and hi…
2015
16 pages, 8 figures, 8 tables
Changes in behavioural response of Mediterranean Seabass (Dicenthratus labrax L.) under different feeding distributions
2009
Captive-induced behavioural deviations may involve many aspects of fish behaviour such as swimming activity and enhancement of individual aggressiveness. We studied seabass (Dicentrarchus labrax) behaviour as a function of manual and automatic feeding distribution modes. Under manual mode, the food is distributed over an extended area for a longer period, and its precise location is not always predictable, while with pneumatic automatic feeders, fish receive the same amount of resource, which is concentrated in the same surface area over a shorter period. We compared seabass behaviour under automatic and manual conditions collecting video image recordings before, during, and after feeding d…
The marine Crustacea Decapoda of Sicily (central Mediterranean Sea): A checklist with remarks on their distribution
2003
A checklist of the Crustacea Decapoda of Sicily, based on pre viously published records and on original data, is presented. The Sicilian waters were divided into three sectors to account for the different habitats present along the northern and western (sector A), eastern (B) and southern (C) coasts, for the sake of a better interpretation of the species distribution. A total of 186 species was recorded between 0 and 800 m depth, 31 of which are re ported here for the first time. Sector A hosted 153 species, B 105 species, and C 117 species. The dissimilarities among the habitats present in the shallow waters of the three sectors accounted for the low co-occurrence of species: 30 species …
First historical records of Carcharhinus brachyurus (Chondrichthyes, Carcharhiniformes) in the Mediterranean Sea
2009
The dried jaws of two specimens of Carcharhinus brachyurus were found in the collections of the Zoological Museum of the University of Palermo. Both pieces belong to the great Doderlein collection of fishes from Sicily assembled during the end of the nineteenth century (1862-1892) and are labelled as Carcarias (Prionodon) lamia and Carcharias lamia, respectively. These findings represent the first historical evidence of the presence of C. brachyurus in the Mediterranean Sea and add the southern Tyrrhenian to the species distribution within the Mediterranean. Moreover, sexual dimorphism in tooth morphology is documented for the first time in Mediterranean specimens. Some meristic and morphol…
Variations in physiological responses to thermal stress in congeneric limpets in the Mediterranean Sea
2014
Cardiac activity (Arrhenius breakpoint temperatures and Q10 relationships) and heat shock response (hsp70 expression) were measured in the congeneric limpets Patella rustica, P. caerulea and P. ulyssiponensis in order to test the relationship between their vertical distribution and physiological thermal tolerance. These species exhibit different vertical distributions along Mediterranean shores and despite the narrow tidal range in the Mediterranean, they experience different environmental conditions and consequently had specific thermal windows. Cardiac activity of the upper zoned P. rustica was maintained at higher temperatures than its mid- or low shore counterparts, P. caerulea and P. u…