RESUMO
Sharks play a key role in the functioning of marine ecosystems and maintenance of trophic web balance, including life cycles of parasites co-occurring in their habitats. We investigated the structure of parasite communities of three sympatric shark species (Etmopterus spinax, Galeus melastomus, and Scyliorhinus canicula) and explored both the influence of host features in shaping the communities and their role as biological indicators of environment stability in the Gulf of Naples (central Mediterranean Sea), a geographical area characterized by strong anthropic pressure. Parasites found were all trophic transmitted helminths with a complex life cycle, except Lernaeopoda galei, that is a ecto-parasite copepod. Communities were all similarly impoverished with 4-5 component species and low values of species richness and diversity. Higher abundance of cestode larvae of the genus Grillotia was found in G. melastomus, although their dominance in all host species suggests that the three sharks have a similar role as intermediate/paratenic hosts in local food webs. Similarly, high abundance of Grillotia larvae could also suggest the occurrence of high abundance of largest top predators in the area. Host morphological (fork length in S. canicula and G. melastomus and body condition index in G. melastomus) and physiological (sex and gonadosomatic and hepatosomatic indices in S. canicula) variables were differently correlated to parasite community structures depending by host species. Potential reasons for the present impoverished parasite communities are discussed.
Assuntos
Cestoides , Copépodes , Parasitos , Tubarões , Animais , Ecossistema , Cadeia Alimentar , Estágios do Ciclo de Vida , Mar Mediterrâneo , Tubarões/fisiologiaRESUMO
The complete nucleotide sequence of the mitochondrial (mt) genome of the demersal zebra seabream Diplodus cervinus (Lowe, 1838) was determined for the first time. The double stranded circular molecule is 16,559 base pairs (bp) in length and encodes for the typical 37 metazoan mitochondrial genes, and 2 non-coding regions (D-loop and L-origin). The gene arrangement of the D. cervinus mt genome follows the usual one for fishes. The nucleotide sequences of the mt protein coding and ribosomal genes of D. cervinus mt genome were aligned with orthologous sequences from representatives of the Sparidae family and phylogenetic relationships were inferred. Maximum likelihood analyses placed D. cervinus as a sister species of Diplodus sargus (Linnaeus, 1758).
RESUMO
Seafloor pollution by benthic litter is an emerging phenomenon, although debris colonization by biota remains largely unexplored. We characterized the litter of the continental slope (~400-600 m) of the Gulf of Naples (Mediterranean) and investigated its fouling biota through integrative taxonomic approaches. Plastic pieces (82 %) with land-based origin (96 %) and limited sizes (10-20 cm) were the items most commonly encountered, suggesting a transfer to deep waters through floating and sinking. The majority of the items were not fouled, and the debris hosted an impoverished biota, leading to hypothesize that benthic litter supports wide communities only in shallow waters. Higher colonization rates were observed for gastropod and cephalopod eggs with no preference for materials and sizes, suggesting that even small pieces of soft plastic provide a spawning habitat for molluscs and affect species' connectivity in the deep-sea ecosystem. Holistic approaches are necessary to evaluate interactions between litter and biota.
Assuntos
Ecossistema , Monitoramento Ambiental , Animais , Mar Mediterrâneo , Moluscos , Plásticos , Resíduos/análiseRESUMO
Natural products and their synthetic analogs and derivatives are a traditional source of bioactive molecules with potential development as drug candidates. In this context, Marine Natural Products (MNPs) represent a rich reservoir of diverse molecular skeletons with potential pharmacological activity that, so far, has been mostly explored in cancer and infectious diseases. Starting from the development of a novel bioassay-guided screening platform for immunomodulatory compounds from an in-house MNPs library, we report the identification of the alkaloid lepadin A as a new model compound for immune-based anticancer activity with characteristics that suggest a possible mechanism as Immunogenic Cell Death inducer. The work describes the molecular-based bioprospecting in the Gulf of Naples together with the bioassay-guided fractionation, the chemical characterization of the alkaloid, and the biological activity in mouse dendritic cells (D1).
Assuntos
Alcaloides , Antineoplásicos , Produtos Biológicos , Alcaloides/química , Alcaloides/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Produtos Biológicos/química , Morte Celular Imunogênica , Camundongos , QuinolinasRESUMO
The invasive fan worm Branchiomma luctuosum (Grube, 1870), originally described from the Red Sea, is first reported here from the Albanian coasts, based on records held in Vlora Bay, a locality near to Valona harbour and Narta Lagoon. Possible pathways of arrival in the area are uncertain. However, species' larval ecology and life-history traits suggest a secondary spreading through shipping. Social media data mining allowed the confirmation of its establishment in the area, with specimens showing high densities in shallow waters on artificial hard substrates and to backdate its arrival in the area since at least November 2016. Citizen science continues supporting marine biology in the Mediterranean area, especially in countries where proper field studies and research projects are still limited.
RESUMO
Eriocheir sinensis is included among the 100 most invasive aquatic invertebrates due to its colonization history and the impacts to biodiversity and economy in the newly invaded environments. Despite of that, its attempts of colonization of the Mediterranean basin seem to have failed so far. In this paper, we summarize the status and the distribution of the species in the Mediterranean and report a further finding from the northern Adriatic Sea, confirmed through an integrative taxonomy approach. We finally discuss the vectors of introduction that may be at the basis of the present record, highlighting the unexplored possibility that an undetected population is already thriving in the area. Whatever of the hypotheses done here is true, the Adriatic Sea could be a new perfect house for this invader, suggesting that more attention should be paid by stakeholders in preventing rather than in remediating possible impacts.
Assuntos
Braquiúros , Animais , Biodiversidade , InvertebradosRESUMO
Pomadasys incisus is a thermophilous coastal subtropical fish species belonging to the family Haemulidae. Originally described from Gambia, this species is widely distributed in the Eastern Atlantic from Galicia to South Africa. It has also been recorded in the Mediterranean Sea since 1840, presumably expanding its distribution in the next decades, although the species could have been already present in the basin, but simply overlooked until the mid XIX century. In this study, we first record P. incisus from Cyprus (eastern Mediterranean Sea), based on two opportunistic observations obtained through a citizen-science project and review the distribution of this species in the Mediterranean Sea. The present sighting raises the question on whether this species is a late arrival in the country or its presence has just been neglected until now. Based on present data, the most likely hypothesis is the latter one, with P. incisus occurring in low densities and being overlooked due to the absence of field studies. Whatever is true, some intrinsic or extrinsic factors may have played a role in limiting its spread or wide establishment in the above-mentioned country.
RESUMO
Areas subjected to anthropogenic impacts are important to test the effect of stressors on local biota. We assessed with trawl net the composition and abundance of megafauna, litter, and litter-fouling communities in the soft bottoms of the National Interest Priority Site (NIPS) of Bagnoli-Coroglio (Gulf of Naples, Tyrrhenian Sea) at different depths. The megafauna accounted for 3444 specimens referred to 133 taxa (91 invertebrates and 42 fishes), for a biomass of ~102 kg and including species of wide ecological and commercial interest. Metrics of community structure yielded high values. The NIPS, hence, is characterized by a high biodiversity. Litter accounted for 3590 items, mostly in plastic and ranging between 10< × ≤20 cm, for a weight of ~260 kg, with values of 299.2 item/km2 and 21.67 kg/km2. The putative origin of most items was land-based (83.6%), whereas sea-based litter accounted for 16.4%. More than 50% of the litter items found showed colonization by invertebrates and/or molluscan egg masses. Marine benthic litter, thus, locally constitutes a complex issue since litter items hosted complex communities of fouling organisms. Future remediation procedures should take the resident NIPS biota into account and not disrupt the environmental balance of the area.