On two Eudendrium (Cnidaria, Hydrozoa) species from the Mediterranean Sea

Two species referable to the genus Eudendrium Ehrenberg are recorded from the central Mediterranean Sea. Eudendrium merulum is reported for the jirst time outside Australia, whereas Eudendrium carneum is recorded for the second time from Mediterranean waters. The structure of the nematocysts of E. merulum is elucidated by SEM analyses and the mechanism of penetration is compared to that of other hydroid

Variability of species’ roles in marine communities: change of paradigms for conservation priorities.

The structure and organisation of aquatic communities, moulded in each environment by combinations of abiotic factors, recruitment and productivity rates, rely upon a network of both pairwise and transitive interactions among organisms. In many cases, a few strong interactors drive basic ecological processes by playing a leading role in channelling the available resources. Among these, keystone species may control the outputs of local biodiversity through large indirect effects, disproportionately large relative to their abundance. Functional roles are not fixed labels, and species interactions have variable outputs in both time and space: also, in spite of a growing literature on species interactions, terminology is often poorly applied. This leads to the loss of the informative value of concepts, like the keystone species, which might represent useful trade-offs between science and environmental politics. Species’ roles are often used to set taxonomic conservation priorities, although this might even be regarded as unethical, ecologically wrong, or in disregard of the evolutionary meaning of species coexistence and interaction. A re-assessment of species’ roles is given here, attempting to highlight their limits and applicability. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00227-001-0769-2

On the origins and evolution of hydromedusan life cycles (Cnidaria, Hydrozoa).

Selected Symposia and Monographs U.Z.I., 6

The westernmost record of Rhopilema nomadica (Galil, 1990) in the Mediterranean - off the Maltese Islands

peer-reviewe

Back with a bang – an unexpected massive bloom of Cassiopea andromeda (Forskaal, 1775) in the Maltese Islands, nine years after its first appearance

The upside-down jellyfish—Cassiopea andromeda (Forsskål, 1775)—is considered an established alien within the eastern Mediterranean Sea, but the species exhibits a highly sporadic occurrence further west within the basin. This study reports the second documented bloom of the species within coastal waters in the Maltese Islands and the third bloom of the species in the westernmost part of the eastern Mediterranean, a full nine years after its first appearance in this part of the Mediterranean.peer-reviewe

Mediterranean jellyfish as novel food: effects of thermal processing on antioxidant, phenolic, and protein contents

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How Much Recurrent Outbreaks of the Moon Jellyfish May Impact the Dynamics of Bacterial Assemblages in Coastal Lagoons?

The moon jellyfish Aurelia coerulea (Scyphozoa) is one of the most common and largest jellyfish inhabiting coastal lagoons, confined bays, and marinas of temperate and subtropical coastal waters. The annual population dynamics of A. coerulea along with some bacterial parameters (bacterial size and biomass, total coliforms, faecal coliforms, intestinal enterococci, culturable Vibrio spp., and culturable bacteria at 37 degrees C), sea surface temperature (SST), salinity, and an array of nutrients (ammonia, nitrites, nitrates, phosphates, silicates, total nitrogen, and total phosphorus) were assessed in the Varano lagoon (Adriatic Sea) that is subject to anthropogenic pollution. Statistical analyses revealed that jellyfish outbreaks and their consequent biomass deposition significantly correlated to seawater temperature, total nitrogen, phosphates, and ammonia concentrations while negative correlations appeared with nitrite and nitrate concentrations. In addition, bacterial biomass and Vibrio abundance correlated with each other and temperature, jellyfish density, and total nitrogen. These findings suggest that environmental changes could trigger the occurrence of jellyfish bursts in the lagoon which, in turn, may act as one of the central drivers of processes regulating some bacterial components. The positive relationship between jellyfish flush-and-crash dynamics and SST suggests that ongoing global warming will seemingly increase jellyfish outbreaks

The attitudes of Italian consumers towards jellyfish as novel food

Abstract The 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

Hydrozoan species richness in the Mediterranean Sea: past and present

The Mediterranean hydrozoan fauna (Siphonophora excluded) comprises 400 species; most (68%) occur in the Atlantic Ocean, 20% are endemic to the Mediterranean, 8% are of Indo-Pacific origin, and 4% are non-classifiable. There are 69 nonindigenous (NIS) species in the basin: 44% of these are casual (recorded just one or very few times), 28% established (widely recorded in the basin), 6% invasive (established NIS that are able rapidly or largely to dissemi- nate away from the area of initial introduction, having a noticeable impact on the recipient community), and 22% questionable (of doubtful taxonomic sta- tus). Entry through the Suez Canal and range expansion through the Gibraltar Strait, often enhanced by ship traffic, appear to be the main processes for recent species introductions, but uncertainties remain for many NIS. Species additions immediately result in larger local or regional species pools, but the newcomers might impact on populations of native species, altering extinction probabilities. A more reliable evaluation of the species pool can be accom- plished by adding new species when they enter the taxonomic record (i.e. the records of any taxon in all types of literature), and by removing species that have not been found for a ‘reasonable’ time (e.g. several decades). Of the 400 non-siphonophoran hydrozoan species known to occur in the Mediterranean Sea, positive records in the last 10 years are available for 156 species (39%), whereas records of the remaining 244 species are older than a decade: 67 spe- cies have not been recorded for 41 years, 13 for 31–30 years, 79 for 21– 30 years, and 85 for 11–20 years

First Evidence of Inbreeding, Relatedness and Chaotic Genetic Patchiness in the Holoplanktonic Jellyfish Pelagia noctiluca (Scyphozoa, Cnidaria).

none6Genetic drift and non-random mating seldom influence species with large breeding populations and high dispersal potential, characterized by unstructured gene pool and panmixia at a scale lower than the minimum dispersal range of individuals. In the present study, a set of nine microsatellite markers was developed and used to investigate the spatio-temporal genetic patterns of the holoplanktonic jellyfish Pelagia noctiluca (Scyphozoa) in the Southern Tyrrhenian Sea. Homozygote excess was detected at eight loci, and individuals exhibited intra-population relatedness higher than expected by chance in at least three samples. This result was supported by the presence of siblings in at least 5 out 8 samples, 4 of which contained full-sib in addition to half-sib dyads. Having tested and ruled out alternative explanations as null alleles, our results suggest the influence of reproductive and behavioural features in shaping the genetic structure of P. noctiluca, as outcomes of population genetics analyses pointed out. Indeed, the genetic differentiation among populations was globally small but highlighted: a) a spatial genetic patchiness uncorrelated with distance between sampling locations, and b) a significant genetic heterogeneity between samples collected in the same locations in different years. Therefore, despite its extreme dispersal potential, P. noctiluca does not maintain a single homogenous population, but rather these jellyfish appear to have intra-bloom localized recruitment and/or individual cohesiveness, whereby siblings more likely swarm together as a single group and remain close after spawning events. These findings provide the first evidence of family structures and consequent genetic patchiness in a species with highly dispersive potential throughout its whole life cycle, contributing to understanding the patterns of dispersal and connectivity in marine environments.Aglieri G; Papetti C; Zane L; Milisenda G; Boero F; Piraino SAglieri, Giorgio; Papetti, C; Zane, L; Milisenda, Giacomo; Boero, Ferdinando; Piraino, Stefan