1,721,254 research outputs found
The adaptive pattern of growth and reproduction of the colonial hydroid Clavopsella michaeli (Berrill, 1948). HYDROBIOLOGIA
No full textThe effects of variations in temperature, salinity and water movement on the laboratory growth and
reproduction of a single clone of the bougainvilliid hydroid Clavopsella michaeli were examined. Unfavourable
conditions resulted in reproducible oscillations of growth rate. They ranged from overall stimulatory
effects (hormesis) to irreversible inhibition and shrinkage of colonies. Exposure to low concentrations
(0.1-5 jug 1- ') of copper and mercury ions produced similar responses, which were therefore regarded
as non-specific. A control mechanism, dampening these growth rate oscillations, supported higher
colonial tolerance, that is adaptation, to environmental stresses of low intensity. When the counteractive
capacity of the control mechanism was exceeded, inhibition occurred. Higher frequencies of gonozooids
were observed in stressed colonies and were interpreted as an adaptive response
Zonation and ecology of epiphytic hydroids in a Mediterranean coastal lagoon: the "Stagnone" of Marsala (North-West Sicily)
No full textForeword to the Hydrozoan Society 7th Workshop Proceedings
No full textForeword to the Hydrozoan Society 7th Workshop Proceedings (Editorial
Nematocysts of the Mediterranean hydroid Halocordyle disticha
No full textThe morphology, distribution and function of nematocysts in the hydroid Halocordyle disticha were studied by light and scanning electron microscopy. Two types of stenoteles, two types of microbasic b-mastigophores (one with a capsular inclusion) and one type of desmoneme were identified. Prey-capturing experiments were performed with Artemia sp. nauplii. Stenoteles and microbasic mastigophores (those with inclusions) penetrated and paralyzed Artemia larvae, whereas desmonemes kept them in a firm grip by winding around setae. © 1991 Kluwer Academic Publishers
The attitudes of Italian consumers towards jellyfish as novel food
Full text linkThe globalization of food markets and the recent upgrade of the European regulation on novel foods open up new possibilities for the introduction of edible jellyfish in the diet of Europeans. In spite of no tradition of eating jellyfish in Italy and, more generally, in Western countries, several Mediterranean jellyfish species have biological and nutritional features with a large potential as innovative, sustainable novel food and source of bioactive compounds. To evaluate the Italians’ attitude of considering jellyfish as food source, a survey has been carried out on a group of 1445 individuals. A questionnaire was designed to assess the jellyfish consumption attitude (JCA) of respondents and explore the effect of their individual traits (socio-demography, personality, behavior habits, neophobia, disgust sensitivity) on JCA. Gender, age, and travelling habits differently affected JCA. Possible culinary uses and food pairing of jellyfish were also significantly influenced by JCA. Individuals with the highest propensity to accept jellyfish as food are young people, familiar with the sea environment, with high education level or students, and frequent travelers. Food neophobia and sensitivity to disgust are confirmed as personality traits able to strongly impair the acceptability of a novel food. Finally, this work provides insights into the acceptance and rejection variables that should be taken into account when an unfamiliar new food product, such as jellyfish, is planned to be introduced in a new dietary culture and new markets
Mediterranean jellyfish as novel food: effects of thermal processing on antioxidant, phenolic, and protein contents
Full text linkFishery, market and consumption of edible jellyfish are currently limited in western countries by the lack of market demand for jellyfish products and the absence of processing technologies adequate to the western market safety standards. The development of technology-driven processing protocols may be key to comply with rigorous food safety rules, overcome the lack of tradition and revert the neophobic perception of jellyfish as food. We show thermal treatment (100 °C, 10 min) can be used as a first stabilization step on three common Mediterranean jellyfish, the scyphomedusae Aurelia coerulea, Cotylorhiza tuberculata, Rhizostoma pulmo, differently affecting protein and phenolic contents of their main body parts. The antioxidant activity was assessed in thermally treated and untreated samples, as related to the functional and health value of the food. Heat treatment had mild effect on protein and phenolic contents and on antioxidant activity. The jellyfish Rhizostoma pulmo, showed the better performance after thermal treatment
A sea of fireworms? New insights on ecology and seasonal density of Hermodice carunculata (Pallas, 1766) (Annelida) in the Ionian Sea (SE Italy)
No full textQuantitative studies on population dynamics and life history traits of key species are useful to predict changes in the structure and organization of biological communities. In this context, Hermodice carunculata (Pallas, 1766) is a selective scavenger/carnivore polychaete species (known as a fireworm) that, in recent years, has exhibited a northern expansion along the whole basin, including the Italian coasts, and an increasing abundance in its southern areas. Here we report ecological data and fireworm abundances from two shallow stations of the Salento peninsula in the Ionian Sea (Lecce, Italy), characterized by different hydrodynamic exposure levels and structural communities. The observed densities by visual census in the years 2019–2021 (up to 18 ind./15 m2) document a striking shift compared to the past anecdotal reports of the rare occurrence of fireworms along the studied area. Additionally, their abundance seems to be driven by the substrate coverage; in fact, a higher density of fireworms was observed where the biodiversity is richer. Results from this study will serve as a baseline reference for future investigation of the invasiveness potential of a species that can act as a biological marker of ocean warming
Evaluation of the efficiency of different harvesting methods of olives
No full textThis paper reports the results of experimental tests carried out in Sicily about the harvesting of olives. Three varieties were selected (Biancolilla, Cerasuola and Nocellara del Belice); the tests were performed in three different periods with three different harvesting systems: manual, manual with pneumatic combs and mechanical harvesting.
The aim of this study was to evaluate the work capacity and productivity of the three harvesting systems and the period maximising the mechanical harvesting efficiency. The damages caused to the trees after mechanical harvesting with a variable frequency shaker were also evaluated. Naturally fallen olives, Jean’s maturity index, detachment force, harvesting efficiency, mean mass of olives and specific oil production of the mechanical harvesting were determined in the three periods.
The results show that the best work capacity and work productivity were obtained during the mechanical harvesting of the variety Nocellara del Belice. Jaen’s maturity index values corresponding to the highest mechanical harvesting efficiency were 1,96 for Nocellara del Belice, 2,38 for Cerasuola and 2,94 for Biancolilla.
It was found that the damages on the trees bark after the use of the shaker can be reduced greasing the sheath of the harvesting head every thirty trees
Jellyfish bioprospecting in the mediterranean sea: Antioxidant and lysozyme-like activities from aurelia coerulea (cnidaria, scyphozoa) extracts
Full text linkMarine invertebrates represent a vast, untapped source of bioactive compounds. Cnidarians are represented by nearly 10,000 species that contain a complex mixture of venoms, collagen, and other bioactive compounds, including enzymes, oligosaccharides, fatty acids, and lipophilic molecules. Due to their high abundance in coastal waters, several jellyfish taxa may be regarded as candidate targets for the discovery of novel lead molecules and biomaterials and as a potential source of food/feed ingredients. The moon jellyfish Aurelia coerulea is one of the most common jellyfish worldwide and is particularly abundant in sheltered coastal lagoons and marinas of the Mediterranean Sea, where it first appeared—as an alien species—in the last century, when Pacific oyster cultivation began. In the present study, the antioxidant and lysozyme antibacterial activities associated with extracts from different medusa compartments—namely the umbrella, oral arms, and secreted mucus—were investigated. Extracts from the oral arms of A. coerulea displayed significant antioxidant activity. Similarly, lysozyme-like activity was the highest in extracts from oral arms. These findings suggest that A. coerulea outbreaks may be used in the search for novel cytolytic and cytotoxic products against marine bacteria. The geographically wide occurrence and the seasonally high abundance of A. coerulea populations in coastal waters envisage and stimulate the search for biotechnological applications of jellyfish biomasses in the pharmaceutical, nutritional, and nutraceutical sectors
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