1,721,150 research outputs found
Schroederella laubieri n. sp., a new species of the subfamily Protoariciinae (Polychaeta, Orbiniidae), with some notes on the genus Schroederella Laubier, 1962
No full textExogone cognettii n. sp., a new species of the subfamily Exogoninae (Polychaeta, Syllidae) collected in the Bay of Calvi (Northern Corsica)
No full textOn the occurrence of the silverstripe blaasop Lagocephalus sceleratus (Gmelin, 1789) along the Libyan coast
Full text linkFive 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
Recruitment of Posidonia oceanica on rubble mounds: substratum effects on biomass partitioning and leaf morphology
No full textLeaf traits and biomass allocation to leaves (aboveground), roots and rhizomes (belowground) were assessed in Posidonia oceanica stands that had recently colonised rubble deposits at Capo Feto (Sicily). Comparisons were made with an adjacent pristine location (matte) at 5, 10 and 15 m depth and for crests, sides and valleys in the rubble deposits.
Leaf traits of P. oceanica shoots were found to differ significantly between the rubble field and the matte. Leaf surface area was greater on the matte (mean adult leaves 200 15 cm(2)/shoot) than at rubble locations (mean adult leaves 35 5 cm(2)/shoot). At a smaller scale, differences also occurred within the rubble locations, with valley locations having greater leaf surface area than sides or crests. Overall, biomass allocation to the roots was higher in the rubble deposits with highest values in valleys (145.4 +/-22.5 g DW m(-2)) compared to the matte (12.6+/- 1.5 g DW m(-2)). An opposite pattern was recorded for leaf biomass, with highest values in the matte (1036.5+/- 64.7 g DW m(-2)) and no significant among between all other locations (average 13.8+/- 1.2 g DW m(-2)).
We concluded that (1) P oceanica leaf traits vary in relationship to substratum type (rubble versus matte); (2) once fragments recruit on rubble, biomass allocation is skewed towards the roots to increase anchorage; (3) root development affects biomass allocation to the leaves, so that aboveground biomass is reduced in plants on rubble mounds compared to the undisturbed meadow
FEEDING-HABITS OF YOUNG-OF-THE-YEAR GREATER AMBERJACK SERIOLA DUMERILI (RISSO, 1810) ALONG THE N/W SICILIAN COAST
No full textA survey was carried out from July to December 1992 in the Gulf of Castellammare (N/W Sicily) in order to study the feeding habits of juveniles of the greater amberjack Seriola dumerili. Stomach content analysis showed three different phases of predation during this period, depending on the size variation of the specimens. Cluster analysis suggested prey choice differed within three size groups. Class I (individuals up to 80 mm SL) feed mainly on the zooplankton community (Copepoda and Crustacea larvae). Class II (individuals ranging from 80 to 120 mm SL) represent a transition stage in which fish continue to feed on zooplankton, but benthic and nectonic items also become important. Class III (individuals greater than 120 SL mm) feed mainly on nectonic and nectobenthic items. Fish belonging to the size class II showed the highest value of niche breadth. The role of the Cymodocea nodosa system is stressed as an energy supply of invertebrate and vertebrate food items, especially to the size class II, in which fish shift from a planktivorous to a piscivorous diet. Further research is needed to understand better the feeding rhythm, food consumption and the role of benthic communities in the diet of this species
Dinamica dell’ecosistema roccioso dell’AMP “Isola di Ustica” nell’ultimo cinquantennio attraverso la conoscenza dei veterani del mare.
No full textI dati di monitoraggio attualmente disponibili per le aree marine protette (AMP) mediterranee risultano
nella maggior parte dei casi limitati nel tempo. Per ovviare a tale mancanza, si possono sfruttare le
conoscenz
First estimates of density and distribution of the alien crab Percnon gibbesi (Decapoda, Percnidae) in the “Capo Gallo-Isola delle Femmine” MPA
No full textNest guarding behaviour of a temperate wrasse differs between sites off Mediterranean CO2 seeps
Full text linkOrganisms may respond to changing environmental conditions by adjusting their behaviour (i.e., behavioural plasticity). Ocean acidification (OA), resulting from anthropogenic emissions of carbon dioxide (CO2), is predicted to impair sensory function and behaviour of fish. However, reproductive behaviours, and parental care in particular, and their role in mediating responses to OA are presently overlooked. Here, we assessed whether the nesting male ocellated wrasse Symphodus ocellatus from sites with different CO2 concentrations showed different behaviours during their breeding season. We also investigated potential re-allocation of the time-budget towards different behavioural activities between sites. We measured the time period that the nesting male spent carrying out parental care, mating and exploring activities, as well as changes in the time allocation between sites at ambient (~400 μatm) and high CO2 concentrations (~1000 μatm). Whilst the behavioural connectance (i.e., the number of linkages among different behaviours relative to the total amount of linkages) was unaffected, we observed a significant reduction in the time spent on parental care behaviour, and a significant decrease in the guarding activity of fish at the high CO2 sites, with a proportional re-allocation of the time budget in favour of courting and wandering around, which however did not change between sites. This study shows behavioural differences in wild fish living off volcanic CO2 seeps that could be linked to different OA levels, suggesting that behavioural plasticity may potentially act as a mechanism for buffering the effects of ongoing environmental change. A reallocation of the time budget between key behaviours may play a fundamental role in determining which marine organisms are thriving under projected OA
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