The pen shell Pinna nobilis (Linnaeus, 1758) is the largest endemic bivalve mollusc of the Mediterranean Sea, listed as an endangered species in the European Union. Because no information is available about the adaptation of pen shells to different habitats, herein the fundamental conditions of adaptation of P. nobilis to peculiar natural environments, such as the Strait of Messina (SM) and the meromictic Faro Lake (FL; Sicily, Italy), were explored by assessing the morphology, mucous production, osmoregulation and neurotransmission of their gills. Although gills of the pen shells from both sites exhibited a regular morphology, a higher presence of acid mucous cells was detected in P. nobilis from FL than SM, as well as higher levels of osmolytes but without interfering the osmoregulatory processes. About the functioning of gills, the cholinergic (i.e. acetylcholine and AChE) neuronal system was unaltered between individuals from the two sites, whereas the GABAergic neurotransmission (i.e. 4-aminobutyrate or GABA) was significantly augmented in gills of P. nobilis from FL than SM. This may be an adaptive response to hypoxic conditions in FL, as supported by the increased hypoxia-inducible factor (HIF-1α) in gills of pen shells from FL than SM. Noteworthy, this study reports for the first time the presence of the GABA neurotransmitter within the metabolite profile, obtained by application of a protonic Nuclear Magnetic Resonance (1H NMR)-based metabolomics approach, of a marine bivalve. Therefore, GABA may be suggested as a metabolite biomarker in pen shells. Overall, findings from this study provide new insights on the behavioural and adaptive responses of the pen shell Pinna nobilis settled in different peculiar environments.

In aquatic environments, hypoxia and oxygen-deficient areas are increasing worldwide. Transitions in oxygen levels can influence the production of reactive oxygen species (ROS), eventually leading to oxidative stress. The transcriptional response of oxidative stress biomarkers was evaluated by qPCR in gill tissue from Mytilus galloprovincialis experimentally subjected to 48-h air exposure followed by 48-h re-oxygenation, as compared to normoxic control mussels. Superoxide dismutases (CuZnsod and Mnsod), catalase (cat), and glutathione S-transferase (gst) were over-expressed early after 8-h air exposure and returned to normoxic levels during re-oxygenation. Moreover, the mRNAs and protein expression patterns of heat shock proteins (HSP70 and HSP90) and metallothioneins (MT-10 and MT-20) were modulated by oxygen availability with increased levels during re-oxygenation suggesting the participation of these cytoprotective mechanisms in the physiological oxidative stress response when oxygen concentration was restored. Overall, the observed modulation of the oxidative stress-related and general stress genes indicates that M. galloprovincialis responds to changes in oxygen availability enhancing the antioxidant potential under low oxygen conditions for dealing with the oxidative burst during future re-oxygenation. The present investigation brings further insights in understanding how intertidal molluscs cope with short-term oxygen variations and gives useful biomarkers for environmental monitoring of hypoxic areas that are predicted to occur in the next future.

This work was designed to evaluate the biological effects of petrochemical contamination on marine mussels. Mytilus galloprovincialis, widely used as sentinel organisms in biomonitoring studies, were caged at the "Augusta-Melilli-Priolo" industrial site (eastern Sicily, Italy), chosen as one of the largest petrochemical areas in Europe, and Brucoli, chosen as reference site. Chemical analyses of sediments at the polluted site revealed high levels of PAHs and mercury, exceeding the national and international guideline limits. In mussels from the polluted site, severe morphological alterations were observed in gills, mainly involved in nutrient uptake and gas exchange. Changes in serotonergic and cholinergic systems, investigated through immunohistochemical, metabolomics and enzymatic approaches, were highlighted in gills, as well as onset of hypoxic adaptive responses with up-regulation of hypoxia-inducible factor transcript. Overall, the application of a multi-biomarker panel results effective in assessing the biological effects of petrochemical contamination on the health of aquatic organisms.

Persistent organic pollutants (POPs) are known to act as “obesogens”, being fat-soluble and affecting lipid metabolism. The Atlantic bluefin tuna, Thunnus thynnus, are top pelagic predators prone to bioaccumulate and biomagnify environmental contaminants. This study aimed at evaluating POPs-induced ectopic lipid accumulation in liver of adult tuna from the Mediterranean Sea. PCBs and organochlorine pesticides were measured in tuna liver, and marked morphological changes observed, namely poorly compacted tissues, intense vacuolization, erythrocyte infiltration and presence of melanomacrophages. The expression of perilipin, a lipid-droplet marker, positively correlated with the gene expression of PPARγ, a master regulator of adipogenesis, and its heterodimeric partner, RXRα. Changes in metabolites involved in fatty acid biosynthesis and ketogenesis were also observed. Although male bluefin tuna appeared to be more sensitive than females to the adverse effects of environmental obesogens, the alterations observed in tuna liver of both sexes suggest a potential onset of hepatic steatosis.

Capo Peloro Lagoon is a coastal brackish system in northeastern Sicily (Italy), consisting of Ganzirri Lake and Faro Lake. The biological effects related to physicochemical parameters were assessed in two autochthonous clam species, Tapes decussatus and Tapes laeta, chosen for their abundance and economic interest, collected from the two Ganzirri Lake subbasins. Higher temperature and salinity values along with lower dissolved oxygen levels were recorded at the southernmost (site B) relatively to northernmost (site A) subbasin. A battery of biomarkers was investigated in clam gills, including histomorphological endpoint, cholinergic neurotransmission, oxidative stress, and hypoxia biomarkers. Both clam species from site B showed altered gill histomorphology attributable to inflammatory processes. A compromised cholinergic neurotransmission, stimulation of the antioxidant defense system, and onset of hypoxic adaptive responses were also observed. Overall, data suggest that the environmental variables, as those recorded in the southernmost subbasin of Ganzirri Lake, adversely interfere with the physiological function of the gills, triggering a number of adaptive responses in the clams.

Aquatic organisms experience environmental hypoxia as a result of eutrophication and naturally occurring tidal cycles. Mytilus galloprovincialis, being an anoxic/hypoxic-tolerant bivalve, provides an excellent model to investigate the molecular mechanisms regulating oxygen sensing. Across the animal kingdom, inadequacy in oxygen supply is signalled predominantly by hypoxia-inducible factors (HIF) and Hif-prolyl hydroxylases (PHD). In this study, hif-α 5′-end and partial phd mRNA sequences from M. galloprovincialis were obtained. Phylogenetic and molecular characterization of both HIF-α and PHD putative proteins showed shared key features with the respective orthologues from animals strongly suggesting their crucial involvement in the highly conserved oxygen sensing pathway. Both transcripts displayed a tissue-specific distribution with prominent expression in gills. Quantitative gene expression analysis of hif-α and phd mRNAs from gills of M. galloprovincialis demonstrated that both these key sensors are transcriptionally modulated by oxygen availability during the short-time air exposure and subsequent re-oxygenation treatments proving that they are critical players of oxygen-sensing mechanisms in mussels. Remarkably, hif-α gene expression showed a prompt and transient response suggesting the precocious implication of this transcription factor in the early phase of the adaptive response to hypoxia in Mytilus. HIF-α and PHD proteins were modulated in a time-dependent manner with trends comparable to mRNA expression patterns, thus suggesting a central role of their transcriptional regulation in the hypoxia tolerance strategies in marine bivalves. These results provide molecular information about the effects of oxygen deficiency and identify hypoxia-responsive biomarker genes in mussels applicable in ecotoxicological studies of natural marine areas.

The embryotoxicity of CuO NPs was evaluated in the black sea urchin Arbacia lixula embryos, by using 24-well plates. Fertilized eggs were exposed to five doses of CuO NPs ranging from 0.07 to 20 ppb, until pluteus stage. CuO NPs suspensions in artificial seawater formed agglomerates of 80-200 nm size, and copper uptake was 2.5-fold up in larvae exposed to high NP concentrations in respect to control. Developmental delay and morphological alteration, including skeletal abnormalities, were observed, as well as impairment in cholinergic and serotonergic nervous systems. These findings suggest the potential of CuO NPs to interfere with the normal neurotransmission pathways, thus affecting larval morphogenesis. Overall, the embryotoxicity tests are effective for evaluation of nanoparticle effects on the health of aquatic biota. Furthermore, as the black sea urchin A. lixula demonstrated to be vulnerable to NP exposure, it may be a valid bioindicator in marine biomonitoring and ecotoxicological programmes.

In aquatic environments, bivalve molluscs are used as sentinel species for environmental biomonitoring. In this study Pinna nobilis specimens, the biggest Mediterranean bivalve, were collected in the Magaluf bay (Mallorca), a touristic location and in a pristine area of the Cabrera National Park as the control location. Histological and histochemical analysis in gills of specimens sampled from Magaluf exhibited evident tissue alterations with high presence of haemocytes. Lower acetylcholinesterase (AChE) activity and protein expression were also found in the gills of specimens collected from Magaluf compared with the control area. The determination of antioxidant enzyme activities, such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, showed a higher activities of these antioxidant enzymes and total glutathione content in samples from Magaluf bay than in Cabrera. In conclusion, the present study demonstrated that human activities result in morphological tissue alterations and a reduced AChE activity in gills of P. nobilis. Moreover, these stressful environmental conditions induced an adaptive response in P. nobilis as evidenced by increased antioxidant defences and a decreased AChE activity.Capsule: The human activities induce oxidative stress in P. nobilis as evidenced by increased antioxidant defences and a decreased acetylcholinesterase activity. (C) 2015 Elsevier Inc. All rights reserved.

Silvia Tejada , Antoni Sureda , Ainhoa Zuazu , Miguela Mendez , Antonino Natalotto , Salvatore Fasulo , Salud Deudero University of the Balearic Islands / Experimental Laboratory, Research Unit, Son Llatzer Hospital, IUNICS, Palma de Mallorca, ES, Research Group on Community Nutrition and Oxidative Stress, IUNICS, University of the Balearic Islands, Palma de Mallorca, Spain and CIBER: CB12/03/30038 Fisiopatologia de la Obesidad y la Nutricion, Instituto de Salud Carlos III (ISCIII), Palma de Mallorca, ES, Spanish Institute of Oceanography, Palma de Mallorca, ES, Dep. of Animal Biology and Marine Ecology, University of Messina, Messina, IT

The diet and prey selectivity of the red mullet, Mullus barbatus, on a sandy bottom of the Tyrrhenian Sea were examined, in respect of season, size and depth, focusing on the use of the surf zone as a feeding ground. Stomach contents of 99 specimens collected by beach seine (in the surf zone) and 568 specimens collected by trawl net (at 10, 20 and 30 m depths) were analysed. The overall diet of M. barbatus was dominated by crustaceans, mainly gammarids, while molluscs and polychaetes are secondary prey taxa. The diet composition of red mullet at each specific depth was related to the availability of prey in the benthic community: mysids were mostly preyed on in the surf zone, while gammarids, decapods and copepods were the principal crustacean prey organisms at other investigated depths. Red mullet in the surf zone mainly preyed on mysids and bivalves in summer and on cumaceans, gammarids and polychaetes in winter. At the other depths, seasonal variation in diet composition reflected the fluctuations of gammarid abundance in the environment; no differences in diet by size were detected. As a result, M. barbatus in the southern Tyrrhenian Sea can be considered as an opportunistic predator of benthic organisms, relying predominantly on crustaceans.

Multiple anthropogenic activities present along coastal environments may affect the health status of aquatic ecosystems. In this study, specimens of European sea bass (Dicentrarchus labrax) were exposed for 30 days to highly contaminated sediment collected from the industrial area between Augusta and Priolo (Syracuse, Italy), defined as the most mercury polluted site in the Mediterranean. The aim was to evaluate the responses of juvenile D. labrax to highly contaminated sediments, particularly enriched in Hg, in order to enhance the scarce knowledge on the potential compensatory mechanisms developed by organisms under severe stress conditions. Apoptotic and proliferative activities [cell turnover: Proliferating Cell Nuclear Antigen (PCNA) and FAS Ligand (FasL)], onset of hypoxic condition [hypoxia: Hypoxia Inducibile Factor-1α (HIF-1α)], and changes in the neuroendocrine control mechanisms [neurotransmission: Tyrosine Hydroxylase (TH), Choline Acetyltransferase (ChAT), Acetylcholinesterase (AChE), 5-Hydroxytryptamine (5-HT) and 5-Hydroxytryptamine receptor 3 (5-HT3)] were investigated in sea bass gill tissues. In the specimens exposed to the polluted sediment, the occurrence of altered cell turnover may result in impaired gas exchange that leads to a condition of "functional hypoxia". Changes in neurotransmission pathways were also observed, suggesting a remodeling process as an adaptive response to increase the O2-carrying capacity and restore the normal physiological conditions of the gills. Overall, these findings demonstrated that although chronic exposure to heavy metal polluted sediments alters the functioning of both the nervous and endocrine systems, as well as plasticity of the gill epithelium, fish are able to trigger a series of physiological adjustments or adaptations interfering with specific neuroendocrine control mechanisms that enable their long-term survival.

Environmental pollutants exert immunotoxical effects on aquatic organisms. The aim was to determine the antioxidant response, markers of oxidative damage and reactive oxygen species production in hemocytes of Pinna nobilis, the largest endemic bivalve in the Mediterranean Sea, under anthropogenic pressure. P. nobilis individuals were collected from two locations along Mallorca Island waters attending to different degree of human impact and the hemocytes were obtained. Specimens from the impacted area showed increased activities of the antioxidant enzymes - catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase -, myeloperoxidase activity and reduced glutathione levels. No differences in oxidative damage markers - malondiandehyde and carbonyl index - were evidenced between the pristine and polluted areas. Hemocytes from the polluted area presented increased capability to generate reactive oxygen species and nitrite/nitrate when activated. In conclusion, the human activities primed hemocytes for oxidative burst and increased the antioxidant mechanism without evidence of oxidative damage. (C) 2013 Elsevier Ltd. All rights reserved.

We investigated the haemolytic capacity of the crude venom extracted from isolated nematocysts of Pelagia noctiluca (Cnidaria: Scyphozoa), and evidenced the proteic fractions responsible for this activity. The nematocyst venom was used at various concentrations to evaluate the haemolytic activity and the lysosomal membrane stability of red blood cells of two teleostean species treated with the extract. The nematocyst extract was assayed against erythrocytes of the two teleostean species living in different environments, Carassius auratus as a common freshwater species, and Liza aurata as a representative of seawater species. Experiments on the haemolytic activity of P. noctiluca in the presence of lipid components of erythrocyte membranes showed that sphyngomyelin strongly inhibited this activity. The crude venom was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis SDS-PAGE and high performance liquid chromatography (HPLC) to detect the proteic composition, and it was found that the active haemolytic components of this venom are distributed in at least four protein fractions. The results of our experiments indicated that Pelagia noctiluca venom induces haemolysis and lysosomal membrane destabilisation in both species and that Carassius auratus was more susceptible to jellyfish venom than was Liza aurata. No significant differences in glutathione (GSH) levels were observed between control and treatments; consequently the toxins do not cause the oxidative stress but likely recognize specific targets (i.e. sphyngomyelin) in the plasmatic membrane of red blood cells.

Biogeographia vol. X)Ol - 2011 (Pubblicato il 23 dicembre 2011) La Biogeografla de//a Sicilia Presenza di Ommdstrep/765 ezzrzfmmzi (Mollusca, Cephalopoda) nelle acque dell’Arcipelago delle Isole Eolie ANTONIO POTOSCHI, FRANCESCO LONGO, ANDREA POTOSCHI, ANTONINO NATALOTTO Dzpartimento dz’ Bio/ogid Animzzle ed Eco/ogia Marina, Universitzi degli Studi dzq Messimz, Salim Sperone 31, 981665. Agata, Messimz (Italy); e—mzzz'[: zz_potoscbz'@unz'me. it Key words: Ommzzstrep/Jes bzzrtramii, fishing, distribution, Eolian Islands, Mediterranean. SUMMARY The neon flying squid, Ommastrep/Je: bartrzzmii (Mollusca, Cephalopoda), lives in epipelagic and mesopelagic waters, over a large bathymetric range, from the surface to about 1500 m depth. In the Mediterranean sea, 0. bar- trzzmii has been reported in small numbers and it is still considered rare. From September 2007 to October 2008, 379 specimens of O. bzzrtramii were sampled in the waters off Eolian Islands (Southern Tyrrhenian Sea). The re- ported sizes range between 18 mm ML and 654 mm ML; the last ones resulted to weigh around 10 kg. INTRODUZIONE Ommczstrepbes earmzmii (Lesueur, 1821), mollusco cefalopode teutoideo, per la sua distribuzione geografica ‘e considerata una specie cosmopolita ed ha una distribuzione batimetrica che Va da 100 In a 1500 In di profondita (Roper et al.,1984). Nel Mediterraneo, finora, e stata segnalata in maniera discontinua ed e indicata come specie rara 0 di difficile reperimento (Guerra, 1992; Salman et al., 2002) (Fig.1). La rarira della specie nei mari italiani e testimoniata da isolate segnalazioni di ritrovamento o addirittura da riferimenti museali da parte di Gamulin—Bri— da e Ilijanic (1965) e da Guescini e Manfrin (1986) per il basso e rnedio Adria— tico; da Torchio (1967) per il Golfo di Taranto; da Biagi (1990) per il Canale di Corsica; da Ragonese er al. (1992) per il Tirreno Meridionale; da Orsi Reli- ni (1990) per le coste Liguri; e pi1‘1 recentemente da Bello (2007) per il Golfo diTaranto (Fig.1). Tale sporadicita pare debba essere ridimensionata in quanto, da alcuni anni,

Aquatic ecosystems are affected by all the impacts generated by a variety of anthropogenic activities present along coastal environments. The sediment compartment is the final receptor of water-insoluble pollutants, acting both as a sink and as a source of pollutants to the water column, and affecting both nektonic and benthic organisms. The aim of this study is to assess the impact of metals in the sediments collected from two sites in the petrochemical area between Augusta and Priolo (SR, Sicily, Italy) on gills of Dicentrarchus labrax. This was done to enhance the scarce knowledge on the bioavailability of metals bound to sediment and their capacity to interact with the bioindicator species. Various sublethal endpoints were assessed such as histopathological lesions, metallothioneins (MTs) and molecules involved in the homeostasis pathways by immunolocalization and RT-PCR. In the specimens exposed to sediments, the data suggested a reduction of gill cell membrane permeability, which could result in altered osmotic balance and gas exchange. Further, an increase of MT expression was detected, consisted the involvement of this protein in detoxification of toxic non-essential metals. The findings of this study demonstrate that a subchronic test, conducted by using sensitive and sub-lethal endpoints, in combination with chemical analyses, is a powerful tool for early identification of environmental hazards associated with contaminated sediments.