Search results for " MEDITERRANEAN SEA"
showing 10 items of 245 documents
Probable root structures and associated trace fossils from the Lower Pleistocene calcarenites of favignana island, southern italy: dilemmas of interp…
2012
Two types of large, branched structures from the Lower Pleistocene (Calabrian) high-energy calcarenites of Favignana Island are described: Faviradixus robustus gen. et sp. nov. and Egadiradixus rectibrachiatus gen. et sp. nov. They may be interpreted as root structures of large plants, trees and trees or shrubs, respectively. The former taxon co-occurs with the marine animal trace fossils Ophiomorpha nodosa , Ophiomorpha isp., Thalassinoides isp. and Beaconites isp. The interpretation as root structures although tentative is probable and can be related to short emergence episodes for the formation of E . rectibrachiatus or to longer emergence, responsible for the discontinuity at the base o…
Prvi nalazi dinoflagelata roda Dicroerisma (Actiniscales, Dinophyceae) na Sredozemnom moru
2011
This study is the first to describe and illustrate the dinoflagellate genus Dicroerisma in the Mediterranean Sea. Twenty individuals ascribed to Dicroerisma psilonereiella were encountered. The highest abundance (12 cells L-1) was recorded in the Balearic Sea at 50 m depth. Other specimens were found in subsurface waters (>75 m depth, with some records at 250 m depth) in the Ionian and Levantine Basin. These findings suggest that Dicroerisma is a widespread genus and its presence has gone unnoticed due to its small size, deep water distribution and misidentification with other gymnodinioid cells.
Mediterranean coccolith ecobiostratigraphy since the penultimate Glacial (the last 145,000years) and ecobioevent traceability
2015
The Mediterranean Sea is a miniature ocean ideal to test the response of marine ecosystems to amplified orbital and suborbital climate changes. Here we present coccolith data from a Sardinia Channel gravity core (Arcose C_33) analysed over the last 145,000 years, with a mean resolution of about 900 years. The study highlights that regional phytoplankton assemblages underwent significant modifications between the penultimate glacial and the last interglacial, as well as between the last glacial and the Holocene. The N ratio palaeoproductivity index suggests reduced productivity levels and the development of a deep nutricline during the last interglacial and the Holocene. Within the last glac…
The marine crustacea decapoda of Sicily: a cecklist with remarks on their distribution.
2003
A checklist of the Crustacea Decapocla of Sicily, based on previously 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, vas recorded between 0 and 800 in depth, 31 of which are reported 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 w…
PAROLE MIGRANTI TRA ORIENTE E OCCIDENTE
2015
L’immagine che oggi il Mediterraneo offre è lungi dall’essere rassicurante. Ai nostri giorni si può dire che le sue opposte rive non abbiano in comune che le loro insoddisfazioni. E sempre più si percepisce questo mare come spazio di attraversamenti intollerati. Percepire il Mediterraneo partendo dal suo passato rimane tuttavia un’abitudine tenace, e a volte viene da pensare che la retrospettiva prevalga sulla prospettiva. La retrospettiva è però irrinunciabile, oggi più che mai. E lo è nel momento in cui la realizzazione di una convivenza in seno ai territori multietnici, là dove si incrociano e si mescolano culture, religioni, lingue diverse, conosce sotto i nostri occhi uno smacco crudel…
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…
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…
Biochemical genetic differentiation between Pomatoschistus marmoratus and P. tortonesei (Pisces, Gobiidae).
1999
Several diagnostic genetic markers were identified in Pomatoschistus marmoratus and P. tortonesei using polyacrylamide gel electrophoresis (PAGE) of allozymes. Twenty-one loci were resolved, including the electrophoretic pattern of muscle proteins. The MDH*, PGM- 1,2*, EST-1,2*, FUM* and PGI-2* loci exhibited different alleles which were fixed for the two species being analysed. Genetic distance, as calculated by Nei’s index, showed a value of 0·413. Environmental hypersalinity, could have influenced the geographical distribution of P. tortonesei.