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…

DISTRIBUTION PATTERNS OF TWO LABRID SPECIES IN THE WESTERN MEDITERRANEAN: IS WATER WARMING AFFECTING THEIR ECOLOGICAL INTERACTIONS?

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), …

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…

DNA-Barcoding to solve the tricky case of co-occuring Sabellaria (ANNELIDA) species in the Mediterranean Sea

Intraspecific morphological variation of key taxonomic features is probably responsible for frequent misidentification of Sabellaria (Lamarck, 1818) species. This is the case of Sabellaria alcocki Gravier, 1906 whose Mediterranean records probably refer to juveniles of S. spinulosa (Leuckart, 1849). We hereby provide molecular tools (DNA barcoding) to improve correct delimitation of the Mediterranean species of this genus.

Escape reaction of the sea-urchins Paracentrotus lividus and Arbacia lixula from the sea star Marthasterias glacialis on different substrates with different structural complexity.

Effetti indiretti del pascolamento dei ricci sul benthos costiero: variazioni nella malacofauna.

Movement pattern of spawners of white seabream, Diplodus sargus sargus (Linnaeus, 1758), in the gulf of Castellammare (NW Sicily)

Benthic megafauna distribution in two different algal assemblages of the Ustica Island rocky infralittoral (NW Mediterranean)

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…

DIEL ACTIVITY AND HOME RANGE OF THE WHITE SEABREAM DIPLODUS SARGUS SARGUS (LINNAEUS, 1758) IN THE GULF OF CASTELLAMMARE (NW SICILY)

Impatto di Caulerpa Taxifolia var. Distichophylla su macro- e meiofauna associate a Posidonia oceanica

Macro- and meiofauna associated with Posidonia oceanica meadows colonized by the invasive alga Caulerpa taxifolia var. distichophylla (Caulerpales) in southern Sicily were analyzed and compared with assemblages of control meadows from the same area. Independently from the degree of invasion (severe or partial), the affected macrofaunal assemblages significantly differed from the controls with the former ones characterized by an increase of molluscs and polychaetes and the decrease of crustaceans. Meiofaunal assemblages showed contrasting results being affected by severe algal invasion but not significantly differing from control assemblages under partial invasion conditions, suggesting some…

Effetti del comportamento di Thalassoma pavo sul successo predatorio di Marthasterias glacialis

New body metrics to determine asteroid size and weight directly in the field

Asteroids are an important group of predators in many marine ecosystems. The measure of body size is crucial in studying asteroid biology as this variable affects both prey selection and predation impact. Current field techniques for estimating asteroid size (i.e. total length TL, total weight TW) include the measure of correlated variables, such us the central disk (CD) and arm length (AL). However, these variables are often time-consuming and require a direct handling of the organism. We tested the accuracy of new asteroid body metrics, the arm height (AH) or arm width (AW), to rapidly estimate body size in asteroids. AH and AW were measured in three of the most common Mediterranean aster…

Unveiling the secrets of a successful invader: preliminary data on the biology and the ecology of the crab Percnon gibbesi (H. Milne Edwards, 1853).

Species richness and coastal biodiversity of Ustica island (pg Tyrrhenian Sea, Mediterranean)

First Mediterranean record and DNA-Barcode of Eulalia ornata (PHYLLODOCIDAE, ANNELIDA) associated to Sabellaria alveolata (SABELLARIIDAE, ANNELIDA)reef.

Dati preliminari sul movimento di Paracentrotus lividus ed Arbacia lixula sul barren habitat

Appendix B. Description of the field methods of the 40 studies used in the meta-analysis.

Description of the field methods of the 40 studies used in the meta-analysis.

Appendix A. Location, design, and other characteristics of the European marine reserves included in the meta-analysis.

Location, design, and other characteristics of the European marine reserves included in the meta-analysis.

Appendix C. List of the species recorded from the studies and their commercial and ecological categories.

List of the species recorded from the studies and their commercial and ecological categories.

Appendix D. Pairwise Pearson correlation coefficients between the commercial and ecological traits considered in the meta-analysis.

Pairwise Pearson correlation coefficients between the commercial and ecological traits considered in the meta-analysis.

Appendix E. Number of species in each combination of commercial category and ecological trait.

Number of species in each combination of commercial category and ecological trait.