0000000000176232
AUTHOR
S. Vizzini
Feeding preferences of Paracentrotus lividus exposed to native and non-native macroalgae
The effects of alien macroalgal invasions on ecosystem functioning may depend on the feeding choice of native herbivores between native and non-native algae. The co-occurrence of two invasive Caulerpa species, C. taxifolia var. distichophylla and C. cylindracea in Southern Sicily, offered the possibility to investigate the feeding preferences of a generalist native grazer, the sea urchin Paracentrotus lividus, for native vs non-native food. A multiple choice feeding experiment was set to assess whether and to which extent P. lividus consumes the exotic macroalgae while in presence of the preferred native ones. Multiple choice feeding assays were run with the following food sources simultane…
Food web reconstruction gives evidence of increased trophic levels in no-trawl areas: the red mullet, Mullus barbatus L. case in northern Sicily
This study was aimed at identifying the food web of the red mullet, Mullus barbatus in order to understand how it is affected by trawling disturbance. To achieve this objective: a) the main features of the red mullet habitat were investigated; b) the food web of this habitat was studied in two no-trawl areas and in two areas open to trawling. The working hypothesis is that trawling affects the biochemistry of the sediment and the trophic structure of the benthic assemblage. It was predicted: a) less biomass, smaller size and higher production rate in the benthic assemblages of protected gulfs; b) higher average trophic level for both the red mullet and its predators in protected gulfs; c) a…
Habitat effect on distribution and feeding of Ophidiaster ophidianus (Lmk.) (Asteroidea)
The purple starfish Ophidiaster ophidianus is an Atlanto-Mediterranean starfish protected under the EU’s Habitats Directive. Despite the wide distribution and the current range expansion of this warm affinity species in the northern Mediterranean areas, nothing is known about its diet. Using field observations and carbon (δ13C) and nitrogen (δ15N) stable isotopes, we explored possible changes in density and diet of O. ophidianus in relation to two different Mediterranean habitats: the coralline barren and the macro algae forest. Data were collected at the Marine Protected Area of Ustica Island (Southern Tyrrhenian Sea) from June to September 2009. Starfish density was not affected by the ha…
Notes on the Biology and Ecology of Opeatogenys gracilis (Canestrini 1864) (Pisces: Gobiesocidae) from Coastal Environments in Sicily (Mediterranean)
A particularly large number of specimens of the Mediterranean coastal fish Opeatogenys gracilis (Canestrini 1864) (Pisces: Gobiesocidae) were collected from Posidonia oceanica mats of the “Stagnone di Marsala” sound (western Sicily) and in the Gulf of Carini (northern Sicily). A study was made of biometric and meristic characters and, for the first time for this species, diet composition. The biometric and meristic data did not distinguish between specimens from the two study sites. In accordance with its benthic habit, O. gracilis feeds on small phytal prey living on Posidonia oceanica leaves. The preferential food items throughout the year were Copepoda Harpacticoida.
Trace metal contamination in a mediterranean coastal pond (Acquatina, Puglia)
As the interface between land and sea, transitional areas are often negatively impacted by anthropic activities. This impact is the result of many processes, including direct input of pollutants which accumulate in both sediments and aquatic organisms. The aim of this paper is to identify trace metal (As, Cd, total Hg and Pb) contamination in the Acquatina pond (Apulia, Italy), using sediment and fish (A. boyeri, C. labrosus, D. annularis, D. dentex, D. sargus, D. vulgaris, E. encrasicholus, G. paganellus, L. ramada, M. surmuletus, S. salpa, S. solea) as descriptors. Sampling was carried out in three stations (South, Central and North) and four seasons (summer and autumn 2007, winter and sp…
The trophic role of the macrophyte Cymodocea nodosa (Ucria) Asch. in a Mediterranean saltworks: Evidence from carbon and nitrogen stable isotope ratios
A multiple stable isotope analysis (δ13C and δ15N) was used to determine the trophic role of the seagrass Cymodocea nodosa (Ucria) Asch. for consumers in a Mediterranean saltworks. Stable carbon and nitrogen isotope ratios performed on primary producers and consumers in February and July 1999 showed that C. nodosa is not a direct dietary source via grazing. No animal presented carbon values as enriched as the seagrass (-7.8‰). The trophic role of Cymodocea occurs through the detritus route via SOM. Sedimentary organic matter (SOM) (δ13C = -16.5‰) seems to be a mixture of particulate organic matter (δ13C = -19.0‰), algae (δ13C = -18.6‰) and seagrass detritus (δ13C = -7.7‰). The results of a …
Acquatina Lagoon: a model ecosystem to study community patterns
Acquatina is a small lagoon ecosystem (0.45 km2) located on the Adriatic coast only 5 km north of Lecce (Italy). The lagoon has a freshwater input in the northern part and a connection with the sea at the south edge, being characterised by a latitudinal gradient of salinity and an internal patchiness of habitats. Here, we have used the lagoons as a model to study the influence of these sources of variation on the spatial distribution of macrobenthis and fish fauna, using both taxonomic and on taxonomic descriptors. Results showed a non random distribution of both species and functional traits of macroinvertebrate and fish fauna within the lagoon, despite the relatively small surface area. S…