Search

Natural storms are able to determine reworking of seabed up to considerable depths and favour suspension of sediment-associated chemicals. Yet, a direct link between exposure to resuspended contaminants and the biological effects on marine organisms have to be fully established. We exposed adults of a suspension feeder, the ascidian Ciona robusta, to polluted sediment (e.g., containing mixtures of polycyclic aromatic hydrocarbons and heavy metals) from the industrial area of Bagnoli-Coroglio under two temporal patterns (‘aggregated’ vs. ‘spaced’) of turbulence events. Then, we assessed the impact of resuspended pollutants on the ascidian gut environment via four broad categories: oxidative stress, innate immunity, host-microbiota interactions, and epithelium. An early oxidative stress response was seen after a week of exposure to static sediment. Instead, water turbulence had no effect on the antioxidant defence. The first episode of turbulent suspension induced a minimal pro-inflammatory response in the ‘spaced’ pattern. Mucus overproduction and a complete occlusion of the crypt lumen were found following sediment reworking. This study suggests a protective response of the gut environment in marine invertebrates exposed to environmental extremes, leading to increased susceptibility to disease and to concerns on the combined effects of chronic environmental contamination and acute disturbance events possibly associated with climate change.

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 simultaneously offered to P. lividus: C. cylindracea, C. taxifolia var distichophylla, a mix of C. cylindracea and C. taxifolia var distichophylla, Dictyopteris membranacea, Cystoseira spp. and a mix of D. membranacea and Cystoseira spp.. Paracentrotus lividus exhibited a stronger feeding preference for the mix of the two exotic macroalgae and for C. cylindracea alone. On the other hand, C. taxifolia var distichophylla resulted barely consumed, although the amount ingested was greater when C. taxifolia var. distichophylla was mixed with the congeneric alga. Our findings confirmed the strong palatability of C. cylindracea and the potential role of P. lividus in controlling the spread of this exotic species. Given the low consumption of C. taxifolia var. distichophylla recorded in this study, it is unlikely that P. lividus may contribute to limit the spread of the new exotic Caulerpa species.

The establishment of non-indigenous species is one of the major threats to Mediterranean biodiversity. The tropical red macroalga Asparagopsis taxiformis is widely distributed in the Mediterranean Sea and appears invasive along the shallow rocky areas of western Sicily (Italy). Here it competes for space with the native brown macroalgae of the genus Cystoseira, in particular with C. brachycarpa, a valuable Mediterranean habitat former. This research aims to evaluate the potential effects of invasion of A. taxiformis on the polychaete assemblages associated with C. brachycarpa. Polychaetes were sorted from Cystoseira and Asparagopsis thalli collected along the Favignana Island (Sicily) in the rocky infralittoral algal community from four locations with different degree of invasion: 1) non-invaded, 2) invaded but dominated by Cystoseira, 3) invaded and dominated by Asparagopsis, 4) completely invaded. Ten replicates of each algal thalli were collected from two sites per location. Structure of polychaete assemblages changed significantly among degree of invasion. Reductions of average polychaete abundance and species richness occurred with invasion, with 58 individuals and 12 species per thallus on non-invaded location, only 4 individuals and 2 species on completely invaded location, and almost equal, intermediate values, on two partially invaded locations. Decrease of abundance was mainly caused by the decrease of sabellid Amphiglena mediterranea and syllids Syllis prolifera and Sphaerosyllis austriaca. These results raise concerns on the spread of non-indigenous habitat forming species and their potential impact on biodiversity at local scale.

Sabellaria alveolata (Linnaeus, 1767), commonly named “sandcastle worm” or “honeycomb worm”, is a gregarious tube-dwelling polychaete building tubes by assembling sand grains and shell fragments with a proteinaceous adesive. The tubes are closely aggregated to form large reefs. These bio-constructions, providing shelter and food to several reefdwelling species, represent a valuable habitat for benthic invertebrates. For this reason, Sabellaria reefs are listed under Annex I of the EC Habitats Directive as a marine habitat to be protected by the designation of Special Areas of Conservation. Sabellaria alveolata reefs are usually intertidal, and sometimes subtidal, at temperate latitudes and they are commonly recorded in the NE Atlantic coast, from Bristol Channel to the Portuguese coast. Reefs are also found in the Mediterranean Sea, where they are usually smaller and less studied than the Atlantic ones. The aim of this study is to improve the knowledge of S. alveolata structures and associated fauna in the Mediterranean area. Reef samples were collected at three Sicilian sites (Sicily Channel), photographed and stored in absolute ethanol. After sorting, the collected specimens were identified at species level and counted. The morphological analysis was integrated by molecular analyses (DNA Barcoding) aimed at confirming the identity of some species of particular interest. Both analyses confirm the presence of two congeneric species in the reefs: S. alveolata, the dominant species, and S. spinulosa. The rest of the associated fauna was mainly composed by other polychaetes and crustacean amphipods. Among the most abundant polychaetes, Eulalia ornata Saint-Joseph, 1888 (Phyllodocidae) resulted new for the Mediterranean Sea. The Mediterranean Sabellaria reefs are a peculiar habitat not yet properly known. Further study would help to better understand the role of S. alveolata as ecosystem engineer and the factors influencing the dynamics of the biogenic reefs in order to promote their conservation.

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 tolerance to the invader.

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.

Shallow hard bottom and intertidal soft bottom polychaete assemblages of the Alexandria coast, south-eastern Mediterranean (Levantine Sea), were studied during a complete annual cycle in order to analyze spatial temporal patterns of variation in assemblages, and relevant factors related to polychaete distribution. The present study recorded a total of 73 species, belonging to Syllidae (22 species), Nereididae (9 species), Serpulidae (6 species), Eunicidae (5 species) and another 19 families. The assemblages experienced pronounced spatial and temporal variation throughout the study area, but spatial variation appeared more important in determining the observed patterns. Polychaete distribution related to variation of grain size and sessile macrobenthos cover suggesting that these structural variables accounted more than the physical-chemical ones (namely BOD, dissolved oxygen, organic carbon, organic matter, salinity, temperature, pH) in influencing the patterns of assemblage distribution. A total of 9 alien polychaete species were found solely on hard substrata, of which Pseudonereis anomala and Linopherus canariensis formed dense population in the area. The present study is the south-eastern-most one dealing with the ecology and distribution patterns of hard bottom polychaetes from the Mediterranean Sea, as well as one of the few studies dealing with intertidal soft bottom polychaetes in the Levant Basin.

The Mediterranean Sea is particularly affected by biological invasions. Alien seaweeds of the genus Caulerpa cause various direct and indirect negative effects on native Mediterranean biota, including changes in benthic assemblages. The northeastern Australian algae C. taxifolia var. distichophylla is a recent invader recorded along the Turkish and southern Sicilian coasts, especially on rocky bottoms and seagrass meadows. The impact of this newcomer on the native Mediterranean benthic communities has not yet been assessed. Herewith the results of the survey carried out in summer 2013, aiming to evaluate the effects of the invasion on the native polychaete assemblages associated to the endemic Mediterranean seagrass Posidonia oceanica are presented. Samples were taken by hand corers on Posidonia meadows borders (mattes) in southern Sicily, where the alien appeared particularly abundant, at invaded and non invaded sites. Polychaetes were more abundant at the impacted sites, while diversity was higher at control sites. Both univariate and multivariate analyses indicated that the composition and structure of the polychaete assemblages in impacted sites was significantly different from those in the control ones. Tolerant capitellids Peresiella clymenoides and Pseudoleiocapitella fauveli and other tolerant species such as Euclymene oerstedi, Glycera tridactyla, Tharyx marioni, Myriochele oculata and Sabellaria spp characterized the impacted location. Differences in Eh and RPD in the mat-associated sediment might be responsible for the observed pattern. Our results raise serious concern about the possible negative effects of the new alien invader on the native macrobenthic fauna.

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

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 tolerance to the invader.

Pinneggiando, a free application for smartphone and tablet, has been developed as a tool for science outreach addressing the interest of both experts and general public. The app concerns the knowledge of biodiversity and distribution of 652 marine organisms in the Italian seas. Based on continuously updated scientific information, Pinneggiando is available at Play Store since January 2014, now reaching more than 1200 downloads with a feedback of 4.65/5. Thanks to this new tool, knowledge on the geographical distribution of many organisms has been expanded by a citizen science approach. Given the rapid success of the initiative, the app will be improved by connecting it to an online database, acting as a "shared repository" of information for an unceasing census of marine flora and fauna.

In the framework of a study carried out along the Belizean coasts, a new species of syllid, Syllis mayeri n. sp., was found harboured by the sponge Ircinia strobilina. The description of this new taxon is given, and compared to other similar congeneric species and to some Mediterranean material from the southern Italian coast ascribed to S. armillaris. The new species is characterized by some stout compound chaetae with ypsiloid appearance, whose probable use for attaching to the host is hypothesized. Other diagnostic features are antennae, tentacular cirri and dorsal cirri of the anterior portion of the body that are longer than in similar, compared species. Moreover, the mid-body dorsal cirri are typically spindle-shaped. A discussion on the status of some sponge-associated taxa from tropical and subtropical seas attributed to the so-called cosmopolitan S. armillaris is also given. Una nueva especie de silido, Syllis mayeri n. sp., se encontró durante la realización de un estudio sobre poliquetos asociados a la esponja Ircinia strobilina en la costa de Belice. En el presente trabajo, se describe el nuevo taxón y se compara con otras especies similares, así como con otro material mediterráneo de la costa del sur de Italia atribuido a S. armillaris. La nueva especie se caracteriza por presentar algunas sedas compuestas engrosadas, de aparencia ypsiloide, que podría usar para engancharse a su huésped. Otros caracteres diagnósticos son la longitud de las antenas, cirros tentaculares y cirros dorsales de la región anterior del cuerpo, mayor que en las especies similares comparadas. Además, los cirros dorsales de la midad del cuerpo son típicamente fusiformes. Se discute también la posición de algunos taxa simbiontes de distribución tropical y subtropical atribuidos a S. armillaris, considerada tradicionalmente como una especie cosmopolita.

Most studies of the polychaete fauna in the Northern Adriatic Sea deal with soft bottoms, while hard bottom studies are very scarce and the last extensive one was conducted by Amoureux in 1975. The Northern Adriatic Sea is a peculiar and sensitive part of the Mediterranean region, currently undergoing through severe changes caused by the combination of natural and anthropogenic factors. In order to get an updated measure of the hard bottom polychaete diversity in the area and assess their spatial distributional patterns, new studies are necessary. In summer 2007 polychaetes were sampled from hard substrate (by scraping off the hard bottom benthos within a 10x10 cm metal frame) on three stations along the Sveti Ivan Island in the vicinity of Rovinj, at 1.5 m, 5 m and 25 m depths. Altogether 103 taxa were found; four species are new for the Adriatic Sea (namely Lepidonotus tenuisetosus, Nereis perivisceralis, N. splendida, N. usticensis), while 19 are recorded for the first time in its northern part. Some newly recorded species are dominant and typical of warmer areas. Multivariate analyses showed that the polychaete assemblages significantly differed both among depths and sites, the two shallower depths being more similar among each other. The depth influenced polychaetes horizontal distribution patterns, since significant differences of both abundance and faunal composition characterised the shallowest assemblages (1.5 m), while at 25 m spatial variability was only due to the abundance. Uncommonly, the lowest horizontal variation of polychaetes distribution was observed at 5 m, although it was expected at 25 m depth due to a higher environmental stability. The high number of newly reported species confirms the importance of regular taxonomic updating of the polychaete fauna in the Northern Adriatic.

In the framework of a study carried out along the Belizean coasts, a new species of syllid, Syllis mayeri n. sp., was found harboured by the sponge Ircinia strobilina. The description of this new taxon is given, and compared to other similar congeneric species and to some Mediterranean material from the southern Italian coast ascribed to S. armillaris. The new species is characterized by some stout compound chaetae with ypsiloid appearance, whose probable use for attaching to the host is hypothesized. Other diagnostic features are antennae, tentacular cirri and dorsal cirri of the anterior portion of the body that are longer than in similar, compared species. Moreover, the mid-body dorsal cirri are typically spindle-shaped. A discussion on the status of some sponge-associated taxa from tropical and subtropical seas attributed to the so-called cosmopolitan S. armillaris is also given.

Sono state illustrate le ricerche condotte per l'evidenziazione e caratterixzazione di composti bioattvi da organismi marini

Checklist delle specie degli anellidi policheti della fauna Italiana