1,721,085 research outputs found
On the coral-feeding habit of Peltaster placenta
No full textThe predatory activity of the asteroid Peltaster placenta (Müller and Troschel, 1842) on the black coral Parantipathes larix (Esper, 1790) is here described for the first time based on video footage obtained during a Remotely Operated Underwater Vehicle (ROV) survey conducted in the Pontine Archipelago (Southern Tyrrhenian Sea, Mediterranean Sea). Feeding is carried out on the living coenenchyme of the basal axis and pinnules of the antipatharian and is confirmed by the occurrence of its cnidocysts in the sea star gut content. The chitinous skeletal parts of the black coral are left intact as bare tissue, which helps to relate colonies to the predation event. Among all black coral species present in the research area, P. placenta was observed grazing exclusively on P. larix, similarly to other goniasterids known to be deep-sea corallivores with a marked selectivity for their prey. The predatory behaviour of P. placenta was previously unknown. The extent of its feeding traces suggests a significant influence on benthic trophic relationships and, ultimately, on the functioning, structure and health status of deep Mediterranean black coral forests
The effects of periodic injections of a synthetic analogue of GnRH in a long acting preparation on the final oocyte maturation of Sparus aurata
No full textEffetti della somministrazione del leuprolide acetato sulla qualità dello sperma crioconservato di Sparus aurata (Perciformes: Sparidae)
No full textSpatial distribution of tube anemones (Ceriantharia) in the Gulf of Naples and Salerno (Southern Tyrrhenian Sea)
No full textCerianthids of the deep Mediterranean circalittoral Sea
No full textDensity and distribution of four species of cerianthids were recorded in three Mediterranean regions: North-West Sicily, Gulfs of Naples and Salerno, and western Ligurian Riviera. Cerianthus membranaceus was recorded in all the studied regions with sparse polyps. Pachycerianthus dohrni was recorded only in the southern regions, while P. solitarius only in the Ligurian Sea. Arachnanthus oligopodus was recorded only in the Gulf of Naples where it may reach very high densities and it is the main element of the soft bottom assemblage
Contribution to the knowledge regarding factors that influence sex inversion in Sparus aurata L. reared in a recirculating system
No full textDeep sponge communities of the Gulf of St Eufemia (Calabria, southern Tyrrhenian Sea), with description of two new species.
No full textRecently, the rich coral communities of the so called roche du large biocoenose of the Gulf of St Eufemia (southern Tyrrhenian Sea) between 90 and 130 m deep, have been described thanks to remotely operated vehicle (ROV) imaging. This preliminary survey evidenced the massive presence of a well-diversified sponge community living among the coral colonies. This work aims at giving an ecological overview of some of the dominant species of this environment, together with a taxonomic part including the description of new species: Topsentia calabrisellae sp. nov. and Haliclona (Soestella) fimbriata sp. nov. The silted, rocky outcrops of the Gulf of St Eufemia facilitate the settling mainly of massive sponges with erect habit which may also avoid sedimentation by growing on the coral colonies. On the other hand, the site Capo Vaticano, located at the southern boundary of the gulf, characterized by rocky boulders exposed to strong currents and completely devoid of corals, is inhabited by a poor megabenthic community, dominated by patches of massive sponges, such as Topsentia vaceleti, a species of recent description whose aspect in the field was still unknown. In the entire investigated area 19 species have been photographed (often for the first time in vivo), collected and identified, but the real sponge diversity is certainly under-estimated due to the difficulty of
collecting all the sighted specimens through the ROV grabber. Similarly to the coral component, sponges also respond to the same environmental constraints by growing in heterogeneous patches or by showing different morphologies mainly associated with current and sedimentation conditions
Effetti del leuprolide acetato sulla biologia riproduttiva dell’orata Sparus aurata (Linnaeus, 1758).
No full textThe gilthead sea bream is a proterandric species that is greatly used in aquaculture. As with most fish reared in captivity, difficulties are encountered in spontaneous reproduction as well as in adequate sex inversion. To obtain further knowledge to improve the rearing of this species, we observed the influence of leuprolide acetate, a synthetic agonist of gonadotropin hormone-release hormone (GnRH), on the reproduction biology of the gilthead sea bream. In particular, we observed the effects of the periodic administration of a long-acting leuprolide acetate on sex reversal and oogenesis of this species reared in controlled conditions. Leuprolide acetate neither stimulated nor inhibited sex inversion, though it anticipated the oocyte maturation and allowed synchrony spawning in all treated females
Economic and sustainability analysis of the camelids meat chain: the case of 'Decama' research methodology
Full text linkThe first phase of the Decama adopted approach for the analysis of domestic South America camelids’ (DSAC) meat chain and for the implementation of private and public interventions to valorize resources and overcome possible bottlenecks is explained. The final aim of such approach is to provide guidelines for the development of sustainable DSAC meat chain in selected South-American countries (Argentina, Bolivia and Peru), were DSAC production is relevant. A proper knowledge of available resources, social and agricultural political interventions, animal agriculture production systems, industrial and commercial enterprises involved in the DSAC meat chain is essential in this first phase. To this aim, social, economic, environmental and institutional data were collected through official statistics and farms/firms questionnaires, which provided the actual image of the general situation of the DSAC meat chain (e.g. herd and natural resource key indicators, demand and supply definitions, chain stadiums and market identification, food quality and safety legislation, labeling systems, government’s influence) and the main enterprises characteristics. For the socio-economic, sustainability and quality certification aspects, three types of questionnaires based on relevant and measurable selected indicators were developed adopting different criteria, with the Business Model (BM) being the most in-deep questionnaire. The BM will allow assessing the technical production systems of 5-7 farms/firms per country (case studies per chain meat stadium) and their related production costs and income. Questionnaires reflected the behaviour of the majority of entrepreneurs of a meaningful number of DSAC enterprises specialized in the production of good located in determined territory. For every chain stadium (i.e. production, processing and marketing), research activities are in progress. The most common models of enterprises in the territories were identified, case studies were selected, common questionnaires for data collection were produced and applied, and results comparison among different models of enterprises in comparable production systems of the three countries is undergoing. Form first results, questionnaire models showed to be suitable to all DSAC meat chains and, if permanently adopted by stakeholders, will represent a useful tool to monitor and detect changes in the DSAC systems for future actions, and to define a guideline framework for sustainable DSAC meat chains in defined landscape units
Habitat, morphology and trophism of Tritonia callogorgiae sp. nov., a large nudibranch inhabiting Callogorgia verticillata forests in the Mediterranean Sea
Full text linkThe continuing exploration of the Mediterranean deep sea reveals that a complete census of the biodiversity of one of the most studied marine areas in the world is yet to be fully accomplished. A tritoniid nudibranch new to science is described upon material recovered off the Montenegro margin, Adriatic Sea, associated with the alcyonacean Primnoidae Callogorgia verticillata (Pallas, 1766). Here, a coral forest dominated by C. verticillata, together with other alcyonaceans, antipatharians and scleractinians, represents the habitat of the new species. As documented by Remotely Operated Vehicle (ROV) observations, the coral forest covers an area of 600 m2 at 420–426 m depth, with dense growth of C. verticillata colonies (1.34 ± 0.08 colonies m−2). As many as 66 nudibranch specimens have been observed on C. verticillata. Tritonia callogorgiae sp. nov. (Gastropoda, Nudibranchia, Tritoniidae) is up to 12 cm long, yellow to orange/reddish in colour with white papillae all over the body. It has a velum with six appendages (three per side), and 4–5 pairs of dichotomous gills. Internally, the species is distinguished from other tritoniids for the absence of stomach plates and a distinctive radula with formula 50 × 110.1.1.1.108. It represents the first case of Tritonia species living in the deep Mediterranean Sea and the only one associated to C. verticillata. Stomach content documents that Tritonia callogorgiae sp. nov. feeds on C. verticillata. Further visual ROV records from other sectors of the Mediterranean Sea indicate that the distribution of this new described species is almost basin-wide. The discovery of another undescribed member of the benthic megafauna related to deep-sea coral grounds further highlights the need for conservation of such habitats
- …
