Marine cyanobacteria are photosynthetic prokaryotes of significant ecological interest, living free or in association with invertebrates. They are also considered as excellent sources of antineoplastic, antibacterial, antiviral and antifungal compounds. In this work, aqueous extracts from eight cyanobacterial strains isolated from the Mediterranean sponge Petrosia ficiformis have been investigated for their bioactive properties. Bioassays with human erythrocytes, Artemia salina nauplii, and Paracentrotus lividus gametes and embryos were performed. Some aqueous extracts exhibited citolytic effect on human erythrocytes and toxic activity against A. sauna nauplii. Furthermore antimitotic activity was evidenced during sea urchin embryos development and disorganization of blasto-meres with altered cell-cell contact was also induced. Some of the isolated cyanobacterial strains, belonging to Leptolyngbya and Synechococcus genera with an high citotoxic activity, should be further investigated to better characterize their bioactive molecules. Our data confirm cyanobacteria as an interesting source of novel bioactive compounds with potential applications in pharmaceutics.

The effects of Ostreopsis cfr. ovata clonal cultures towards the gametes and embryos of the sea urchin Paracentrotus lividus have been evaluated. The benthic dinoflagellate showed a significant toxicity towards sperms which have exhibited a drastic reduction of their fertility with the increasing of the microalgal concentration. A deleterious effect was also observed on the embryos cleavage. These data should be considered preliminary and will help us to better understand the effects that this allochtonous microalga might have on marine life in temperate waters.

A filamentous cyanobacterium (strain ITAC101) isolated from a Mediterranean sponge (Petrosia ficiformis) was characterized by a combined phenotypic and genetic approach. Morphological and ultrastructural observations were performed along with growth measurements and pigment characterization. The molecular phylogenetic analyses were based on the sequencing of the 16S rRNA gene. In culture conditions, strain ITAC101 is moderately halophilic and grew in the range 0.3-7.6% (w/v) salinity with the optimum at 3.6%. Cell dimensions, thylakoid arrangement and pigment composition of this cyanobacterium fit the Halomicronema genus description, and phylogenetic analyses evidenced 99.9% similarity with another strain endolithic in tropical corals. The new Halomicronema metazoicum species was established including the two cyanobacteria associated to marine animals

The planula larva of the hydroid Clava multicornis has a complex nervous system, characterized by the presence of distinct, anteriorly concentrated peptidergic populations of amidated neurons, presumably involved in the detection of environmental stimuli and metamorphic signals. Differently from other hydrozoan larvae, in C. multicornis planulae GLW-positive cells with putative sensory role have a peculiar dome-shaped forefront organization, followed by a belt of RF-positive nerve cells. By immunohistochemistry we investigated the transformation of the peptidergic (GLW-amide and RF-amide) larval neuroanatomy at different stages of metamorphosis and the subsequent development of the primary polyp nervous system. By TUNEL assay, apoptotic nuclei were first identified in the anterior pole of the settled larva, in the same region occupied by GLW-amide positive putative sensory cells. In primary polyps, GLW-amide positive signals first encircled the hypostome area, later extending downwards along the polyp column or upwards over the hypostome dome, whereas RF-amide positive sensory cells initially appeared at the tentacles base to later extend in the tentacles and the polyp column. In spite of the possession of distinct neuroanatomies, different cnidarian planulae may share common developmental mechanisms underlying metamorphosis, including apoptosis and de novo differentiation. Our data confirm the hypothesis that the developmental dynamics of tissue rearrangements may be not uniform across different taxa.

The dinoflagellates of the genus Ostreopsis Schmidt are toxic species involved in the occurrence of massive blooms. These dinoflagellates are known to produce palytoxin and ovatoxins, which are considered amongst the most poisonous phycotoxins in the world. In this work, aqueous and methanolic extracts of one Ostreopsis cf. ovata Ionian strain were tested on the human-derived HeLa cell line, and cytotoxicity, cytoskeletal rearrangement, and apoptosis induction were recorded by morphological and molecular analysis. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test revealed high toxicity for both extracts, which activity was inhibited by ouabain, which suggests the main involvement of palytoxin-like molecules in the observed toxic effects of this strain. Overall, the effects induced by O. cf. ovata on HeLa cells were dependent on the type of adopted extracts, being both toxic, but with the methanolic extract more toxic than the aqueous one and able to induce cell death by apoptosis. This process was evidenced by both phosphatidylserine exposition and upregulation of caspase-3 gene expression. The different effect of the two extracts on cell death is indicative of their different composition and/or activity. Our findings represent the starting step for the characterization of novel bioactive molecule

Echinoderms are a renewable resource with an economic value due to their increasing demand as food and/or source of bioactive molecules exerting antitumor, antiviral, anticoagulant, antioxidant, and antimicrobial activities. In this framework, the present study is aimed at investigating the antibacterial, antioxidant, and hemolytic activities in the three Echinoderm species Echinaster sepositus, Arbacia lixula, and Sphaerechinus granularis. The sea star E. sepositus showed lysozyme-like activity (mean diameter of lysis of 13.4 ± 0.2  mm), an antimicrobial activity against the human emerging pathogens Staphylococcus aureus, Pseudomonas aeruginosa, and Candida famata, and a strong lytic activity (100 ± 0.05%) towards the human red blood cells. Furthermore A. lixula and E. sepositus had the highest antioxidant activity (1792.75 ± 233.7 and 1765.65 ± 484.58 nmolTE/mL, resp.). From toxicological assays, it was shown that E. sepositus was not toxic towards HeLa cells and Vibrio fischeri, encouraging the exploitation of this species in the pharmaceutical field. Therefore, our findings have implications due to the ongoing explosion of antibiotic-resistant infections because of the new opportunistic pathogens and the need to discover antibacterial agents with new modes of action. Also the recorded antioxidant activity taking into account the need to find natural antioxidants useful for human health is intriguing

1 - Coastal marine and transitional water ecosystems are threatened world-wide by invasions of nonindigenous invertebrate species, altering community structure and ecosystem functioning. 2 - Here, we report on the occurrence of the Atlantic blue crab Callinectes sapidus in transitional water ecosystems of the Apulia coastline (Salento peninsula, SE Italy). 3 - Blue crabs were sampled seasonally, every three months over a whole-year period in the Torre Colimena basin (Ionian Sea) and Acquatina lagoon (Adriatic Sea). Specimens were identified and enumerated. In addition, their hemolymph was screened for parasite infections using histological techniques. 4 - Callinectes sapidus was sampled in the Torre Colimena basin, where no other crab species were collected during the whole experimental period. In contrast, in the Acquatina Lagoon four crab species were sampled, including C. sapidus. 5 - The parasitic dinoflagellate Hematodinium sp., known to determine in C. sapidus the degenerative “bitter crab syndrome” in its native habitats, was ubiquitously detected in the hemolymph of blue crabs from both habitats and in autochthonous brachyurans collected in the Acquatina Lagoon. 6 - An assessment of the diverse spectrum of potential ecological effects triggered by the Callinectes-Hematodinium interaction on autochthonous brachyuran species is presented, together with a preliminary evaluation of the molecular approaches to be implemented in order to verify the species-specificity of the host-parasite interaction.

Coastal marine ecosystems world-wide are threatened by invasions of non-indigenous invertebrate species, altering population, community and ecosystem processes. Here, we report on the occurrence of the Atlantic blue crab Callinectes sapidus in coastal habitats of the Salento peninsula (South-East of Italy). Blue crabs and other indigenous crab species were sampled monthly in Acquatina and Torre Colimena basins (Adriatic and Ionian Sea, respectively). Specimens were enumerated, and sexed. In addition, their hemolymph was collected and analyzed using histological techniques. C. sapidus occurred episodically in the Acquatina basin, whereas it was collected during the whole sampling period in the Torre Colimena basin. Immature and mature individuals of both sexes were sampled; in addition, the ubiquitous occurrence in the hemolymph of both C. sapidus and indigenous crab species of the parasite Hematodinium sp. suggested the occurrence of an established population in the basin. A preliminary evaluation of the molecular approaches to be implemented on C. sapidus and its parasites from Torre Colimena to assess the relationship with other established populations in Croatian and Albanian waters is presented. In particular, the transmission of parasites between invasive and indigenous species is generally poorly investigated, and molecular techniques may provide a rapid and effective screening methodology.

In the marine environment organochlorine insecticides can be broadly detected in water, sediments, and biota. These pollutants may have major ecological consequences since they may affect marine organisms and endanger organismal growth, reproduction or survival. In this study we investigated the modification of some sea urchin immunological parameters in response to subchronic lindane (gamma-HCH) exposure. Adult specimens of the sea urchin Paracentrotus lividus were exposed to two different concentrations (0.1 and 0.5 mg L-1) of lindane. After 24 and 48 h of treatment, we examined the lindane influence on coelomocytes vitality and enumeration as well on some humoral parameters. Our results showed that the presence of the pesticide affected both cellular and humoral components of the immune system. In particular, P. lividus coelomocytes vitality did not change but a decrease of the total cell number and an increase of the red cells was recorded. Haemolytic and lysozyme-like activities as well as antibacterial activity on Vibrio alginolyticus of treated animals decreased. Sea urchin immunological competence modifications might represent a tool for monitoring disease susceptibility thus providing biological criteria for the implementation of water quality standards to protect marine organisms

In many coastal areas the abundant proliferation of microalgae producing biotoxins determines the occurrence of Harmful Algal Blooms (HABs). Their presence in temperate waters is well documented and often associated with marine toxin-derived disease. The occurrence and toxicity of three harmful microalgae (Amphidinium carterae, Coolia cfr. monotis and Ostreopsis cfr. ovata) from the northern Ionian Sea (Mediterranean Sea) is hereby reported. The three dinoflagellates were sampled both on macroalgae and water and their morphology and occurrence were compared to those of other Mediterranean sites. The toxicity of the three cultured strains was tested by Artemia salina and hemolysis tests and their effects on the first stages of the sea urchin development was also evaluated. The contemporary presence of the three species inhibited the in vitro sea urchin embryonic development. But this action could be ascribed to the sole Ostreopsis as the addition of the single species to the sea urchins embryos evidenced no effects in presence of Amphidinium or Coolia cells, and an irregular segmentation in presence of Ostreopsis. In particular, this latter species exerted a cytotoxic effect in a dose-dependent manner, with a production of deformed embryos even at very low cell concentration (42 cells mL1). Nevertheless, when algal cell lysate was added, some effects on the sea urchin development was detected for each dinoflagellate, and also in this case Ostreopsis has proved to be the most toxic species. However, the lysate of Amphidinium and Ostreopsis strongly affects the A. salina nauplii vitality, while the hemolytic activity was very low for Amphidinium and Coolia lysate and very strong for Ostreopsis. Our results highlight the importance to monitoring the presence of these dinoflagellates whose effects may also be reflected on the early life stages of marine organisms, especially those species that are important from both an ecological and economic point of view, as the sea urchins are.

Pollution by heavy metals has become one of the most important problems in marine coastal areas as a consequence of anthropogenic inputs. Among metal contaminants, zinc, being considered not very toxic, is sometimes released into the sea in appreciable quantities and its concentration is loosely regulated. In this work we analyzed the effects of a high zinc concentration on the sea urchin Paracentrotus lividus immune system. In particular, after 24 h of zinc treatment, we evaluated coelomocytes morphology and composition as well as the zinc influence on some humoral parameters such as hemolysis, lysozyme-like activity and antibacterial activity on Vibrio alginolyticus. Our results evidenced that the presence of zinc affected both cellular and acellular components of the sea urchin immune system. The P. lividus coelomocytes changed in morphology and number; moreover, the amebocytes changed from a petaloid to a filipodial-like shape and the red spherula cells increased in number. Among the considered humoral effectors lysozyme-like activity and antibacterial activity on V. alginolyticus decreased in short-term to zinc treatment. The modifications in the sea urchin immunological competence might give an early indication of disease susceptibility thus suggesting to consider the examined defence mechanisms as potential biological indicators of metal pollution.