Crostacei Anfipodi associati ai reef di Sabellaria alveolata (Annelida: Sabellariidae) del Canale di Sicilia (Mar Mediterraneo)

We describe diversity and patterns of spatial distribution of the amphipod fauna associated with reefs of the polychaete Sabellaria alveolata (L.) in the Sicily Strait. Samples were collected in June 2013, at three localities. Amphipod assemblages appeared homogeneous in the study area with variability increasing with decreasing spatial scale of observation. Jassa ocia (Bate) and Gammaropsis ulrici Krapp-Schickel & Myers characterized the studied assemblages.

Protection effect on distribution patterns of Paracentrotus lividus and Arbacia lixula in the “Plemmirio” Marine Protected Area

Adhesive root hairs facilitate Posidonia oceanica seedling settlement on rocky substrates

Posidonia oceanica, the dominant Mediterranean seagrass, has been historically described as a species typically growing on mobile substrates whose development requires precursor communities. During more than 10 years of direct observations, we noticed that P. oceanica seedlings were often firmly anchored to rocky reefs, even at exposed sites. Thus, we analysed the ultrastructural features of seedling root systems to identify specific traits that may represent adaptations for early seedling anchorage on rocky bottoms. Subapical sections of adventitious roots were obtained from 2-3 months old specimens collected in the field and were observed at SEM revealing an extensive coverage of adhesive…

Relative role of fish vs. starfish predation in controlling sea urchin populations in Mediterranean rocky shores

In the Mediterranean, fishing bans generally allow the recovery of populations of sea urchin predators, such as the seabreams Diplodus sargus and D. vulgaris, promoting the transformation of overgrazed communities into ones dominated by erect macroalgae. However, in the marine reserve on Ustica Island (SW Italy) the opposite trend has occurred in the upper infralittoral community, and urchin barrens formed after the cessation of fishing activities. We hypothesized that (1) the natural scarcity of the 2 seabream species leads to a low predation rate on sea urchins at Ustica, and (2) predation rate varies with depth, due to differences in the predator assemblages. Tethering experiments were c…