Organometallic complexes with biological molecules

Novel triorganotin(IV) complexes of two beta-lactamic antibiotics, 6-[D-(-)-beta-amino-p-hydroxyphenyl-acetamido]penicillin (=amoxicillin) and 6-[D-(-)-alpha-aminobenzyl]penicillin (=ampicillin), have been synthesized and investigated both in solid and solution states. The complexes corresponded to the general formula R(3)Sn(IV)antib*H(2)O (R=Me, n-Bu, Ph; antib=amox=amoxicillinate or amp=ampicillinate). Structural investigations about configuration in the solid state have been carried out by interpreting experimental IR and 119Sn Mossbauer data. In particular, IR results suggested polymeric structures both for R(3)Sn(IV)amox.H(2)O and R(3)Sn(IV)amp*H(2)O. Moreover, both antibiotics appear …

Hydrodynamism and its influence on the reproductive condition of the edible sea urchin Paracentrotus lividus

Despite the large body of work published in the last two decades on the reproduction of the sea urchin Paracentrotus lividus, the reproductive aspects linked to hydrodynamic conditions and their influence on gonad production remain poorly understood. The present paper aims to evaluate the effect of hydrodynamism on the reproductive cycle of P. lividus. Variability in the gonadosomatic index (GSI) of P. lividus was estimated seasonally from 2007 to 2008 at two shallow sub-littoral flat basaltic areas at Ustica Island (Western Mediterranean). GSI was higher in the sites characterized by low hydrodynamism than in those with high hydrodynamism. Results also suggest a possible role for hydrodyna…

Preliminary data on movement of sea-urchins Paracentrotus lividus and Arbacia lixula in two habitats with different structural complexity.

Fish assemblages cope with ocean acidification in a shallow volcanic CO2 vent benefiting from an adjacent recovery area

Shallow CO2 vents are used to test ecological hypotheses about the effects of ocean acidification (OA). Here, we studied fish assemblages associated with Cymodocea nodosa meadows exposed to high pCO2/low pH conditions at a natural CO2 vent in the Mediterranean Sea. Using underwater visual census, we assessed fish community structure and biodiversity in a low pH site (close to the CO2 vent), a close control site and a far control site, hypothesising a decline in biodiversity and a homogenization of fish assemblages under OA conditions. Our findings revealed that fish diversity did not show a unique spatial pattern, or even significant relationships with pH, but correlated with seagrass leaf …

Notes on the fish assemblages present in the areas invaded by Caulerpa spp. (Ulvophyceae, Chlorophyta) along the Sicilian coasts

Relationship between egg features and maternal body size in the simultaneous hermaphrodite Oxynoe olivacea (Mollusca, Opisthobranchia, Sacoglossa)

This paper provides information on spawn morphology and egg features of the stenophagous planktotrophic Mediterranean sacoglossan Oxynoe olivacea. Smith and Fretwell’s hypothesis, predicting that individuals of the same population growing in the same environmental conditions and varying in size should spawn eggs of a constant size, was tested in a population of O. olivacea living in the Straits of Messina. To determine whether (a) spawn mass size, (b) total egg number per spawn, and (c) egg size were related to parent size of O. olivacea, 21 egg masses (seven egg masses deposited by seven different 20 mm animals, seven egg masses deposited by seven different 25 mm animals and seven egg mass…

Dati preliminari sulla variabilità spazio-temporale di Paracentrotus lividus nell’ AMP “Capo Gallo Isola delle Femmine”

Plp38MAPK activity in embryogenesis, morphogenesis and stress response: an indicator of perfect health?

P38 conveys a variety of signals, including conventional growth, migratory and death signals, as well as responding to environmental and mechanical stimuli. These signals induce phosphorylation of p38, which triggers both its translocation to the nucleus and the activation of its catalytic function. In Paracentrotus lividus we have shown that for a correct cilia re-generation the p38 activation is essential; we also showed, by time course Western blotting, two activation peaks during development (morula and early gastrula stages) with a precise localization of activated p38 in micromere and micromere derived cells (Nichel treatment higlighted this feature), and in the oral apical region. Th…

Exploring the impact of the invasive algae Caulerpa taxifolia var. distichophylla and C. cylindracea on the performance of the sea urchin Paracentrotus lividus.

Food selection of a generalist herbivore exposed to native and alien seaweeds

Understanding which factors influence the invasion of alien seaweed has become a central concern in ecology. Increasing evidence suggests that the feeding preferences of native herbivores influence the success of alien seaweeds in the new community. We investigated food selection of a generalist native grazer Paracentrotus lividus, in the presence of two alien seaweeds (Caulerpa cylindracea and Caulerpa taxifolia var. distichophylla) and two native seaweeds (Dictyopteris membranacea and Cystoseira compressa). Sea urchins were fed with six experimental food items: C. cylindracea, C. taxifolia var. distichophylla, a mixture of C. cylindracea and C. taxifolia var. distichophylla, D. membranace…

Cytogenetic characterization ofBrachidontes pharaonis(Fisher P., 1870): Karyotype, banding and fluorescentin situhybridization (fish) (Mollusca: Bivalvia: Mytilidae)

Abstract The mussel Brachidontes pharaonis (Fisher P., 1870) (Bivalvia: Mytilidae) has a diploid chromosomal set of 28 made up of 14 pairs of which eight are mono-armed (ST) and six bi-armed (M+SM). Fourteen bivalents occur in spermatocytes both at pachytene and metaphase-I. The use of combined silver and CMA3 staining reveals that nucleolus organizer regions (NORs) are located terminally on the long arm of a small subtelocentric chromosome pair (pair 14) and are compartmentalized in GC base pairs. A Paracentrotus lividus (Echinodermata) 4.3 kilobase (kb) rDNA probe (prR14) consisting of sequences from the 3′ end of 18S rDNA to the 3′ end of 26S rDNA was used to map the rDNA loci of B. phar…

Influenza della protezione sulla struttura dei popolamenti algali dell’AMP “Isola di Ustica”, un caso di studio.

The impact of climate change on Mediterranean intertidal communities: losses in coastal ecosystem integrity and services

As has been shown for other ecosystems, the ecological and socio-economic impacts of climate change on Mediterranean intertidal habitats are highly variable in space and time. We conducted field and laboratory measurements of cellular, ecophysiological and behavioural responses of selected intertidal invertebrates (mussels, gastropods and sponges) and completed a literature review to determine what is known of socioeconomic consequences of these biological changes. Results suggest significant gaps in our knowledge that may impede a complete understanding of likely impacts (physical, biological, and socioeconomic) and that sufficient data for such an analysis is available only for mussels. A…

Morphological response of the larvae of Arbacia lixula to near-future ocean warming and acidification

The distribution of the sea urchin Arbacia lixula, a warm affinity species, has been expanding in the Mediterranean Sea. To address questions on potential for future success of this species in the region, the thermotolerance of larval development was investigated in context of regional warming. The larvae were reared in present day spawning period (20 °C) and warming conditions (+4 = 24 and +6 = 26 °C). As the calcifying larvae of sea urchins are vulnerable to stunted growth caused by ocean acidification, the impact of lower pH (−0.3 pH units) on larval development was also investigated in combination with warming. Morphological traits of the larvae, post-oral length arms, overall length of…

Body size and mating strategies in the simultaneous hermaphrodite Oxynoe olivacea (Mollusca, Opisthobranchia, Sacoglossa).

Summary 1To better understand the role and importance of body size in hermaphroditic mating system theory, the mating behaviour of the shelled sacoglossan Oxynoe olivacea was studied. This simultaneous hermaphrodite exhibits bilateral and unilateral sperm transfer and thus it is particularly suitable for studies on hermaphrodite sexual conflict. 2In this study three hypotheses on body size were tested: that O. olivacea partner size has an effect on (i) mating mode choice, (ii) duration of mating modes, and (iii) choice of sexual role. Furthermore, we tested Charnov's hypothesis that in O. olivacea, like many simultaneous hermaphrodites, a sexual conflict exists and the male role is preferre…

La raccolta del riccio di mare Paracentrotus lividus

The recruitment of scallops (and beyond) by two different artificial collectors (Gulf of Taranto, Mediterranean Sea)

This study provides for the first time an evaluation of the natural availability of scallop seeds along the coastal area of Taranto (Mediterranean Sea, Southern Italy). To select the best artificial collectors to harvest scallop seeds in this area, cylindrical collectors (Cyl) were compared to traditional 'Japanese-style onion bags' (Bag) across three sites. Scallops represented 26.6% of total bivalve recruitment among all collectors (782 ± 331 ind. m-2). The most recruited scallops were Flexopecten glaber and Mimachlamys varia. The white (F. glaber) and black scallops (M. varia) were abundant at all three sites, while the queen scallop, Aequipecten opercularis, was only found at one site. …

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

Increased water temperature decreases predation rate of an important sea star predator on sea urchins.

Environmental impact of antifouling technologies: state of art and perspectives

1. Marine fouling affects most man-made surfaces temporarily or permanently immersed in the sea, resulting in significant (or substantial) economic costs. Intense research is aimed at preventing or reducing fouling. 2. The most widespread solution to avoid fouling formation is to make surfaces unsuitable for settlers, coating them with antifouling (AF) paints containing toxic compounds. Most AF agents (e.g. tributyltin, (TBT)) have undesirable effects on non-target species, including commercially important organisms. 3. To date, the use of TBT in AF paints has been restricted (but not prohibited) in a number of countries and new biocides are in use. 4. The environmental problems posed to ma…

Effect of temperature rising and ocean acidification on reproductive success of thermophilic sea urchin Arbacia lixula

Fish-seastar facilitation leads to algal forest restoration on protected rocky reefs

AbstractAlthough protected areas can lead to recovery of overharvested species, it is much less clear whether the return of certain predator species or a diversity of predator species can lead to re-establishment of important top-down forces that regulate whole ecosystems. Here we report that the algal recovery in a Mediterranean Marine Protected Area did not derive from the increase in the traditional strong predators, but rather from the establishment of a previously unknown interaction between the thermophilic fish Thalassoma pavo and the seastar Marthasterias glacialis. The interaction resulted in elevated predation rates on sea urchins responsible for algal overgrazing. Manipulative ex…

Synergistic reduction of a native key herbivore performance by two non-indigenous invasive algae

Abstract Native generalist grazers can control the populations of non-indigenous invasive algae (NIIA). Here, it was found that the simultaneous consumption of two co-occurring NIIA, Caulerpa cylindracea and C. taxifolia var. distichophylla, hinders the grazing ability of the main Mediterranean herbivorous, the native sea urchin Paracentrotus lividus. The ingestion of any of the two NIIA alone did not produce any difference in sea urchin righting time with respect to usual algal diet. In contrast, the simultaneous consumption of both NIIA, which grow intermingled in nature and are consumed by P. lividus, retarded its righting behavior. Such result reveals substantial physiological stress in…

Arbacia

Sea urchins of the genus Arbacia are widely distributed throughout the world occurring in tropical, temperate and sub-Antartic zones. In the past, Arbacia has been the object of intensive investigations in cell biology and biochemistry of fertilization and early development. Renewed interest in the genus Arbacia arose mainly due to its ecological role and its unusual geographic distribution. All the six species of Arbacia are omnivorous with a strong tendency to carnivory. Recent manipulative and morpho-functional studies demonstrated that Arbacia species play an important role in the ecology of rocky reefs. They maintain barren areas by scraping either fleshy and encrusting algae and anima…

Distribution and diet of Marthasterias glacialis at Ustica Island MPA

Distribution and diet of Marthasterias glacialis was studied at Ustica Island MPA. We conducted observations of the asteroid along the upper infralittoral zone using random parallel transects. M. glacialis was more abundant at study sites characterized by low densities of erect algae. Most frequent prey species was a bivalve and sea urchins

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

Functional traits of two co-occurring sea urchins across a barren/forest patch system

Abstract Temperate rocky reefs may occur in two alternative states (coralline barrens and erect algal forests), whose formation and maintenance are often determined by sea urchin grazing. The two sea urchin species Paracentrotus lividus and Arbacia lixula are considered to play a similar ecological role despite their differing morphological traits and diets. The patchy mosaic areas of Ustica Island, Italy, offer an ideal environment in which to study differences in the performance of P. lividus and A. lixula in barren versus forest states. Results show that the two sea urchin species differ in diet, trophic position, grazing adaptation, movement ability and fitness in both barren and forest…

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

Il progetto S.E.P.I.A. (Sperimentazione sull’Educazione Pubblica ed Informazione Ambientale) nell’Area Marina Protetta “Isola di Ustica”.

NUOVA CATTURA DI LOBOTES SURINAMENSIS (BLOCH,1790) IN TIRRENO MERIDIONALE (OSTEICHTHYES: LOBOTIDAE).

The operational sex ratio of the sea urchin Paracentrotus lividus populations: the case of the Mediterranean marine protected area of Ustica Island (Tyrrhenian Sea, Italy)

We investigated, with a series of field and laboratory observations, the possible effect of the starfish Marthasteria glacialis predation on the operational sex ratio (OSR), i.e. the number of sexually mature males divided by the total number of sexually mature adults of both sexes at any one time, of the edible sea urchin Paracentrotus lividus. The OSR was estimated three times during the sea urchin summer spawning period (July 2004, June 2005 and July 2006) on barren substrates of Ustica Island Marine Protected Area (Southern Tyrrhenian Sea, Italy). Four sites were selected: two characterized by high M. glacialis density (take zone C) and two controls with low starfish density (no-take zo…

Antioxidant response, induced by the invasive algae Caulerpa distichophylla and C. racemosa, in the sea urchin Paracentrotus lividus

Effetti della raccolta ricreativa sulla distribuzione di Paracentrotus lividus e Arbacia lixula nell’amp “Isola di Ustica” (Mediterraneo occidentale, Italia).

Cytogenetics in the sacoglossan Oxynoe olivacea (Mollusca: Opisthobranchia): karyotype, chromosome banding and fluorescent in situ hybridization

Developing embryos and sexually mature follicles of the male portion of ovotestis proved to be a suitable material as a source of cleaving cells for advanced cytological investigations on the sacoglossan species Oxynoe olivacea Rafinesque, 1819 (Mollusca: Opisthobranchia). O. olivacea has a diploid chromosomal number of 30 made up of 15 pairs of which six are metacentric/submetacentric (M/SM), four subtelocentric (ST) and five on the borderline between SM and ST. Correspondingly, 15 bivalents occur in spermatocytes at Metaphase I. Constitutive heterochromatin is scarce and restricted to small C-bands seen in five pachytene bivalents. The use of combined silver staining and fluorescent in si…

First estimates of density and distribution of the alien crab Percnon gibbesi (Decapoda, Percnidae) in the "Capo Gallo-Isola delle Femmine" MPA

The rise of thermophilic sea urchins and the expansion of barren grounds in the Mediterranean Sea

Recent ecological studies have shown a strong relation between temperature, echinoids and their grazing effects on macro-algal communities. In this study, we speculate that climate warming may result in an increasingly favourable environment for the reproduction and development of the sea urchin Arbacia lixula. The relationship between increased A. lixula density and the extent of barren grounds in the Mediterranean Sea is also discussed.

Macroalgal forest vs sea urchin barren: Patterns of macro-zoobenthic diversity in a large-scale Mediterranean study.

Abstract The study aimed at contributing to the knowledge of alternative stable states by evaluating the differences of mobile and sessile macro-zoobenthic assemblages between sea urchin barrens and macroalgal forests in coastal Mediterranean systems considering a large spatial scale. Six sites (100 s km apart) were selected: Croatia, Montenegro, Sicily (Italy), Sardinia (Italy), Tuscany (Italy), and Balearic Islands (Spain). A total of 531 taxa, 404 mobile and 127 sessile macro-invertebrates were recorded. Overall, 496 and 201 taxa were found in macroalgal forests and in barrens, respectively. The results of this large-scale descriptive study have met the expectation of lower macrofauna co…

Le aree di transizione siciliane: stato dell’arte e sviluppi futuri

Climate change potentially affect keystone predation in subtidal system.

Feeding strategy of the sacoglossan opisthobranch Oxynoe olivacea on the tropical green alga Caulerpa taxifolia.

The feeding behaviour of the shelled sacoglossan Oxynoe olivacea was investigated to better understand the role and importance of this species in influencing encroachments of the alien alga Caulerpa taxifolia in the Mediterranean sea. We tested whether this slug preferred, as preliminary field observations suggested, an aggregative feeding behaviour and which part of the algal thallus, phylloid vs rhizoid, it preferred. Results showed that O. olivacea fed in groups and actively selected phylloid. This outcome poses important questions regarding the possibility that this species, fragmenting the alga thallus, could enhance dispersion and regeneration of C. taxifolia.

New Mediterranean Marine biodiversity records

Based on recent biodiversity studies carried out in different parts of the Mediterranean, the following 19 species are included as new records on the floral or faunal lists of the relevant ecosystems: the green algae Penicillus capitatus (Maltese waters); the nemertean Amphiporus allucens (Iberian Peninsula, Spain); the salp Salpa maxima (Syria); the opistobranchs Felimida britoi and Berghia coerulescens (Aegean Sea, Greece); the dusky shark Carcharhinus obscurus (central-west Mediterranean and Ionian Sea, Italy); Randall’s threadfin bream Nemipterus randalli, the broadbanded cardinalfish Apogon fasciatus and the goby Gobius kolombatovici (Aegean Sea, Turkey); the reticulated leatherjack St…

The first confirmed record of the Atlantic blue crab Callinectes sapidus Rathbun, 1896 (Decapoda, Brachyura) from Maltese waters

The invasive portunid species Callinectes sapidus is hereby recorded for the first time from Maltese waters, thus updating the known distribution of this decapod of Atlantic origin within the Mediterranean. Potential introduction pathways of the species to Maltese waters are discussed.

Sicilian transitional waters: Current status and future development

To appraise the current knowledge of Sicilian transitional waters (TWs), a review was undertaken of the information available on these ecosystems. In detail, a synthesis of the current status is reported, highlighting for each area the ecological features and status, historical data, conservation regime, environmental emergencies and anthropic pressures to which they are subject. The Sicilian TWs reviewed include coastal ponds and lakes, mires and areas with active and nonactive saltworks. Almost all of these ecosystems are affected by several protection regimes because of their high naturalistic value, although current knowledge is limited and fragmented. A few areas have received more att…

Macroalgal assemblage type affects predation pressure on sea urchins by altering adhesion strength.

In the Mediterranean, sea breams are the most effective Paracentrotus lividus and Arbacia lixula predators. Generally, seabreams dislodge adult urchins from the rocky substrate, turn them upside down and crush their tests. Sea urchins may respond to fish attacks clinging tenaciously to the substratum. This study is the first attempt to investigate sea urchin adhesion strength in two alternative algal assemblages of the rocky infralittoral and valuated its possible implication for fish predation. We hypothesized that (1) sea urchin adhesion strength is higher in rocky shores dominated by encrusting macro-algae (ECA) than in erected macro algae (EMA); (2) predation rates upon sea urchins are …

Remarkable presence of Aplysia punctata (Mollusca, Opisthobranchia, Anaspidea) in the Ustica Island MPA (Western Mediterranean, Italy)

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

Diet and trophic interactions of Paracentrotus lividus and Arbacia lixula in two alternative stable states of the Mediterranean rocky sublittoral community

Espansione di Caulerpa taxifolia (Caulerpales, Ulvophyceae) lungo le coste dell'Isola di Favignana

Changes in spawning-stock structure and recruitment pattern of red mullet, Mullus barbatus, after a trawl ban in the Gulf of Castellammare (central Mediterranean Sea)

Abstract Fiorentino, F., Badalamenti, F., D’Anna, G., Garofalo, G., Gianguzza, P., Gristina, M., Pipitone, C., Rizzo, P., and Fortibuoni, T. 2008. Changes in spawning-stock structure and recruitment pattern of red mullet, Mullus barbatus, after a trawl ban in the Gulf of Castellammare (central Mediterranean Sea). – ICES Journal of Marine Science, 65: 1175–1183. The increase in biomass of red mullet, Mullus barbatus, in the Gulf of Castellammare (northwestern Sicily, central Mediterranean) after a 14-year trawl ban, prompted us to compare the spawning-stock structure and the recruitment pattern before and after the closure. Datasets obtained from three experimental trawl surveys were availab…

Studio preliminare sulla diversità della megafauna dei barren mediterranei

Effects of tri-n-butyltin(IV) chloride on neurulation of Ciona intestinalis (Tunicata, Ascidiacea): an ultrastructural study

This paper reports the cytotoxic effects of tri-n-butyltin (IV) chloride, TBTCl, on the neurulation process of the ascidian Ciona intestinalis. Exposure of the embryos at early neurula stage in 10−5 and 10−7M TBT (IV) chloride solutions for 1–2 h provoked the irreversible arrest of their development. Morphological and ultrastructural observations suggested that most probably there are two principal causes determining the neurulation process block. The first is due to the TBT effects of inhibiting the polymerization and/or degradation of microfilaments and microtubules, proteins that constitute the cytoskeleton. The lack of orientation and extension of both microtubules and microfilaments of…

Leading role of the sea urchin Arbacia lixula in maintaining the barren state in southwestern Mediterranean

Sympatric sea urchin species are usually considered to belong to the same grazer guild. Nevertheless, their role in community dynamics may vary due to species-specific morphological traits, feeding preferences and foraging behavior. In the Mediterranean Sea, the two species Paracentrotus lividus and Arbacia lixula co-occur in barren areas. Whereas P. lividus is usually considered responsible for creating a barren ground, the roles of the two sea urchin species in its maintenance are currently unclear. The relative and combined effects of P. lividus and A. lixula on maintaining the benthic community in the barren state were tested experimentally, using orthogonal exclusion of the two species…

Sea temperature and echinoid Arbacia lixula (L.) population fluctuations on Ustica Island MPA

Much can change in a year: The massawan mantis shrimp, erugosquilla massavensis (Kossmann, 1880) in sicily, Italy

A flourishing population of the Massawan mantis shrimp, Erugosquilla massavensis, an Erythraean species, is recorded off Sicily, Italy, one year after the very first specimen was collected off the eastern coast of the island. The species is already established as a minor, albeit valuable, fishery resource. Once its population increases, however, it may compete with the native Mediterranean spot-tail mantis shrimp, Squilla mantis. This article presents the results of a joint effort between members of the Museo Civico di Storia Naturale of Comiso and local fishermen to monitor non-indigenous species in Sicilian waters.

Nuova Cattura di Lobotes surinamensis (Bloch, 1790) in Tirreno Meridionale (Osteichthyes: Lobotidae).

Effects of temperature rising and ocean acidification on reproductive success in the sea urchin Arbacia lixula (L.)

Relazioni tra parametri biometrici in Marthasterias glacialis (L.) (Asteroidea)

Biometric parameters of the Asteroid echinoderm Marthasterias glacialis (L.) were measured at Ustica Island MPA (SW Tyrrhenian Sea). Wet weight was correlated with tip-to-tip (arm-span) diameter, central disk, arm length, arm width and arm height. Results show high positive correlation between weight and arm height, suggesting a new useful method to estimate starfish size also for in situ measurements.

Size-dependent predation of the mesopredator Marthasterias glacialis (L.) (Asteroidea)

Asteroids are largely recognized as important predators in all of the world’s oceans and for this reason, they play a crucial role in shaping the structure and functioning of benthic ecosystems. The spiny starfish Marthasterias glacialis is generally considered a voracious predator of molluscs, in particular bivalves. Using field observations and carbon (δ13C) and nitrogen (δ15N) stable isotopes, we explored possible changes in diet in relation to size of M. glacialis. Data were collected at Ustica Island (Southern Tyrrhenian Sea) from June 2008 to June 2010. M. glacialis showed a size shift in feeding preferences due to different use of food items: bivalves, Columbella rustica, Euthria cor…

Trophic structure of vermetid reef community: High trophic diversity at small spatial scales

Stable isotopes were used to investigate contributions of autochthonous (i.e. benthic: epilithon and macroalgae) and allochthonous (i.e. pelagic: phytoplankton) organic matter sources to the diet of suspension-feeders, grazers and predators associated to small reef-pools (cuvettes) created by the reef-building species Dendropoma petraeum in the north-western coast of Sicily (Italy). Contributions of potential food sources were calculated using Bayesian mixing-models and integrated to a multivariate approach to highlight the diversity of C and N pathways within Dendropoma cuvettes. Both pelagic and benthic organic matter sources were exploited by benthic consumers, although clear differences…

Trophic Transfer of Trace Elements in an Isotopically Constructed Food Chain From a Semi-enclosed Marine Coastal Area (Stagnone di Marsala, Sicily, Mediterranean)

Trace element accumulation is particularly important in coastal and transitional environments, which act as contaminant buffers between the continental and marine systems. We compared trace element transfer to the biota in two locations with different open-sea exposures in a semi-enclosed marine coastal area (Stagnone di Marsala, Sicily, Italy) using isotopically reconstructed food chains. Samples of sediment, macroalgae, seagrasses, invertebrates, fish, and bird feathers were sampled in July 2006 and analysed for stable carbon and nitrogen isotopes (δ(13)C, δ(15)N) and trace elements (arsenic [As], cadmium [Cd], total mercury [THg], and lead [Pb]). Trophic magnification factors were calcul…

Il Plemmirio e le altre AMP Mediterranee

Sex ratio operativa della popolazione di Paracentrotus lividus (Lam.) nell’AMP Isola di Ustica

Nell’AMP ”Isola di Ustica” l'instaurazione del regime di protezione, e quindi del divieto di prelievo, ha provocato un aumento della densità del riccio edule Paracentrotus lividus (Lam.) con conseguenze negative sulle comunità algali. L’intenso pascolo di questi echinidi regolari ha infatti trasformato la fascia superficiale sommersa in un barren ground, area a bassa complessità e diversità. Una buona stima della sex ratio operativa (OSR) di P. lividus può chiarire aspetti importanti della dinamica di popolazione di questa specie ed essere di notevole aiuto in una logica di intervento gestionale. Scopo del lavoro è stato quello di valutare la OSR della popolazione di P. lividus presente nel…

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

Role of two co-occurring Mediterranean sea urchins in the formation of barren from Cystoseira canopy

Abstract In the Mediterranean Sea the co-occurring sea urchins Paracentrotus lividus and Arbacia lixula are usually considered to share the same ecological role in the formation of barren from Cystoseira canopy. However, their foraging ability may vary due to feeding behavior and species-specific morphological traits. The relative effects of P. lividus and A. lixula on Cystoseira canopy was tested experimentally both in the laboratory, at a density of about 20 ind./m 2 , and in the field by gut content analysis. Field and laboratory results show that A. lixula is unable to affect Cystoseira spp. Furthermore, these results confirmed the great ability of P. lividus to consume Cystoseira canop…

Warmer temperatures reduce the influence of an important keystone predator

Predator–prey interactions may be strongly influenced by temperature variations in marine ecosystems. Consequently, climate change may alter the importance of predators with repercussions for ecosystem functioning and structure. In North-eastern Pacific kelp forests, the starfish Pycnopodia helianthoides is known to be an important predator of the purple sea urchin Strongylocentrotus purpuratus. Here we investigated the influence of water temperature on this predator–prey interaction by: (i) assessing the spatial distribution and temporal dynamics of both species across a temperature gradient in the northern Channel Islands, California, and (ii) investigating how the feeding rate of P. heli…

Influenza della protezione sulla struttura dei popolamenti algali. AMP "Isola di Ustica", un caso di studio

Native predators control the population of an invasive crab in no-take marine protected areas

1. The resistance of an ecosystem to species invasion is considered to be related to the abundance and diversity of native species i.e. biotic resistance hypothesis). Theory predicts that the high native diversity in pristine systems can hinder the establishment and/or the spread of non‐native species through direct and indirect mechanisms (e.g. through competitive and/or predatory interactions). 2. Here we tested whether predation provides higher resistance to invasion by the Percnidae crab Percnon gibbesi (H. Milne Edwards, 1853) in protected native communities, compared with exploited ones. Specifically, this study aimed to compare: (i) the abundance and diversity of potential predator a…

Effect of the two co-occurring sea-urchins Paracentrotus lividus and Arbacia lixula on the maintenance of the barren habitat in the Ustica MPA (NW Mediterranean).

New record of Caulerpa taxifolia (Caulerpales, Ulvophyceae) in the South-western Sicilian waters (Italy).

Analisi preliminare della pesca artigianale nell'area del Biscione (Sicilia sud-occidentale).

Chemoecological study of the invasive alga Caulerpa taxifolia var. distichophylla from the Sicilian coast

Marine invasive species and their bioactive metabolites have become critical ecological issues in the Mediterranean Sea. In particular, the highly invasive green algae Caulerpa taxifolia and Caulerpa cylindracea are known to contain the bioactive sesquiterpene caulerpenyne (1) and the bisindolic alkaloid caulerpin (2), potentially acting as chemical stressors for native species. The recent spread of a variety of C. taxifolia, Caulerpa taxifolia var. distichophylla, also raises urgent questions about its chemical composition. Indeed, the only chemical data available for this alga are limited to the seasonal variations of caulerpenyne (1) in samples collected in the Eastern Mediterranean. In …

Sex allocation in the simultaneous hermaphrodite Aplysia punctata (Mollusca, Opisthobranchia).

Protection effects on feeding and reproduction of Paracentrotus lividus and Arbacia lixula on barren grounds at Ustica Island MPA (Western Mediterranean, Italy).

Effetto del substrato sulla tenacità di attacco e sulla predazione dei ricci Paracentrotus lividus (Lmk) nell’AMP Isola di Ustica.

Hiding behaviour ofOxynoe olivacea(Mollusca: Opisthobranchia: Sacoglossa) in the invasive seaweedCaulerpa taxifolia

The occurrence of the invasive seaweed Caulerpa taxifolia in the Straits of Messina (Italy) provides an excellent opportunity to examine the spatial and temporal patterns of abundance of the endemic Mediterranean sacoglossan Oxynoe olivacea. Densities of this species were recorded in March, June and October 2000 on three different habitats: the underside of boulders (UNB), the upper side of boulders (UPB), and the surface of concrete blocks (CB). Results showed that in March, O. olivacea was consistently more abundant on UNB whereas in June it was present exclusively on CB. The density of O. olivacea was similar in the three habitats in October. The hiding behaviour of O. olivacea and its s…

Dinamica dell’ecosistema roccioso dell’AMP “Isola di Ustica” nell’ultimo cinquantennio attraverso la conoscenza dei veterani del mare.

Stato e conservazione di Paracentrotus lividus nell’ AMP Plemmirio.

A new contribution to the alien macroalgal flora of the Ustica Island Marine Protected Area (Tyrrhenian Sea, Italy)

A second record of the non-indigenous species Botryocladia madagascariensis G. Feldmann (Rhodophyta) along the coasts of the “Ustica Island” Marine Protected Area (Tyrrhenian Sea, Italy) is reported. With this additional record for the Sicilian coasts, we provide a description of collected specimens of B. madagascariensis and habitat details. Numerous fertile female gametophytes with cystocarps immersed in vesicles were also observed, for the second time in the Mediterranean Sea, and described.

A preliminary study on temporal and spatial patterns of variability in Paracentrotus lividus and Arbacia lixula in the Ustica Island MPA (western Mediterranean, Italy). “ Le scienze naturali,economiche e giuridiche nello studio per la gestione degli ambienti acquatici.

Unveiling the diet of the thermophilic starfish Ophidiaster ophidianus (Echinodermata: Asteroidea) combining visual observation and stable isotopes analysis

The starfish Ophidiaster ophidianus is an Atlanto-Mediterranean species protected under the EU’s Habitat Directive. Despite the wide distribution and the current range of expansion of this thermophilic species in the northern Mediterranean Sea, nothing is known about its diet. Using field observations and δ13C and δ15N Stable Isotopes Analysis (SIA), the feeding habits of O. ophidianus were explored in two Mediterranean rocky reef areas located in the southern Tyrrhenian (Ustica Island, Italy) and the eastern Adriatic Sea (Molunat, Croatia). According to field observations, O. ophidianus preys mainly on crustose coralline algae (CCA) and the keratose sponge Ircinia variabilis in both areas.…

Successo di fecondazione di Arbacia lixula: limitazione da sperma e longevità dei gameti

Micropredation on sea urchins as a potential stabilizing process for rocky reefs

Rocky reefs can shift from forest, a state dominated by erect algae with high biodiversity, to barren, an impoverished state dominated by encrusting algae. Sea urchins, abundant in barrens, are usually held responsible for the maintenance of this state. Predation by large fish can revert the barren state to forest by controlling sea urchin populations. However, the persistence of a community state sometimes seems to be independent from the presence of such large predators, suggesting the existence of other, unknown mechanisms ensuring their stability. Theoretical studies suggest that the settler stage of sea urchins is determinant for maintaining a given rocky reef state. In this study, we …

Arbacia lixula pluteus size is shaped by temperature.

Arbacia

Arbacia is unique among shallow echinoid genus, not in line with the general rule that sea urchins should be either entirely tropical or entirely temperate, with limited overlap in the subtropics. Six extant Arbacia species have been described by Mortensen. The genus Arbacia has a Neotropical origin and four different fossil species have been described from the Late Miocene. Over the past century, Arbacia has been the subject of intense investigations into the cell biology, toxicology, biochemistry, and embryology. Recently, renewed interest in this genus arose from its phylogeny, ecology, and its resilience to ocean warming and acidification. According to several studies, impacts of ocean …

Ciclo riproduttivo di Arbacia lixula (Linneo, 1758) (Echinodermata: echinoidea) nella AMP “Isola di Ustica”

Overwiew to the International Workshop “Status and management of the edible sea urchin Paracentrotus lividus in Mediterranea sea”

New Mediterranean Marine biodiversity records (December, 2013)

M. Bilecenoglu [et al.]

Temperature modulates the response of the thermophilous sea urchin Arbacia lixula early life stages to CO2-driven acidification

The increasing abundances of the thermophilous black sea urchin Arbacia lixula in the Mediterranean Sea are attributed to the Western Mediterranean warming. However, few data are available on the potential impact of this warming on A. lixula in combination with other global stressors such as ocean acidification. The aim of this study is to investigate the interactive effects of increased temperature and of decreased pH on fertilization and early development of A. lixula. This was tested using a fully crossed design with four temperatures (20, 24, 26 and 27 °C) and two pH levels (pHNBS 8.2 and 7.9). Temperature and pH had no significant effect on fertilization and larval survival (2d) for te…

Crushing predation of the spiny star Marthasterias glacialis upon the sea urchin Paracentrotus lividus

Literature data report that only fish predators are able to crush sea urchin tests in Mediterranean rocky reefs. This experimental study showed that the spiny star Marthasterias glacialis is able to break Paracentrotus lividus tests and that the breaking event is more likely to occur for small-sized sea urchins than for big ones. Our results show that the role of M. glacialis in regulating P. lividus population density can be important in specific locations. They may have important implications, moreover, for the use of tethering techniques aimed at identifying predator types of sea urchins.

La pesca o meglio la “raccolta” di Paracentrotus lividus in Mediterraneo.

Predation on sea urchin by Marthasterias glacialis (L.).

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…

Mapping the distribution of urchin barren grounds using sidescan sonar: the experience of the “Plemmirio” MPA

In the Mediterranean Sea, high densities of the sea urchins Paracentrotus lividus and Arbacia lixula may promote and maintain formation of areas overgrazed by sea urchins, usually referred to as urchin barrens, leading to drastic changes in ecosystem functioning. Urchin barrens are habitats of low primary production and habitat structure, that negatively affect local biodiversity. At Plemmirio MPA, abundance of both sea urchin species increased dramatically after the start of enforcement in 2005 consequently triggering the formation of “barren” seascape, evidence of a desertification process. This study focuses on the results of a high-resolution Side scan sonar (Klein 3900) surveying carri…

Ruolo ecologico degli Asteroidei in due comunità dell'infralitorale superiore dell'Isola di Ustica

Gli asteroidi sono predatori che si ritrovano comunemente negli ecosistemi marini di fondo duro e mobile. Nell’Area Marina Protetta “Isola di Ustica” il divieto di raccolta del riccio edule Paracentrotus lividus nell’infralitorale superiore, ha determinato la sostituzione della comunità ad alghe fotofile erette con una comunità dominata da alghe incrostanti e ricci (barren) in gran parte dell’isola. Tre specie di asteroidi, Marthasterias glacialis, Ophidiaster ophidianus e Coscinasterias tenuispina, si ritrovano comunemente sia nell’habitat dominato dal barren che in quello dove rimangono elevate coperture ad alghe fotofile erette. Sono state studiate la distribuzione e le abitudini aliment…

First record of Caulerpa taxifolia (Caulerpales, Ulvophyceae) in the western Sicilian waters (Italy).

Visual cues as the key for driving ornate wrasse response behavior

The effects of recreational Paracentrotus lividus fishing on distribution patterns of sea urchins at Ustica Island MPA (Western Mediterranean, Italy)

This study evaluated the effects of recreational Paracentrotus lividus fishing on average density and size of this edible sea urchin, and its indirect effects on Arbacia lixula on barren substrates of Ustica Island MPA (SW Italy, Mediterranean Sea). Size, single and pooled species densities, density of large individuals (>40 mm long) and small individuals (<20 mm long) of the two species were estimated by scuba diving in autumn 2003, spring and summer 2004 at two sites impacted by P. lividus fishing (Punta Cavazzi and Pagliaro, take zone C) and one control (Cala Sidoti, no take zone). Two samplings were performed in each season. We found that reduced densities of P. lividus and A. lixula oc…

Larval Development of Arbacia lixula (Linneo, 1758) in two Marine Protected Area: preliminary data.

The sea urchin Arbacia lixula is a crucial species in driving the algal assemblages dynamic of the infralittoral zone. A. lixula is considered a thermophilic species and its increase in abundance in western Mediterranean waters, probably is due to an increase in seawater temperature. The aim of this study was to examine the reproductive success of A. lixula by larval development. The study was conducted within two Sicilian MPA (Capo Gallo-Isola delle Femmine and Ustica), characterized by photophilic algae, the same exposure and seawater temperature. In each area, twenty random specimens was sampled from May to September 2010, and mature gametes were collected from six males and six females …

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

Effetto della complessità del substrato sulla distribuzione di Paracentrotus lividus e Arbacia lixula nel barren dell?A.M.P. "Isola di Ustica"

Effects of Paracentrotus lividus removal on the co-occurring Arbacia lixula at Ustica Island MPA (Western Mediterranean, Italy)