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Since antiquity, the sense of smell (olfaction) is considered as a distance sense, just like sight and hearing. Conversely, the sense of taste (gustation) is thought to operate by direct contact, similarly to touch. With the progress of natural sciences, information at molecular, anatomical, and neurobiological levels has also contributed to the taste-smell dichotomy, but much evidence inconsistent with a sharp differentiation of these two senses has emerged, especially when considering species other than humans. In spite of this, conflicting information has been interpreted so that it could conform to the traditional differentiation. As a result, a confirmation bias is currently affecting scientific research on chemosensory systems and is also hindering the development of a satisfactory narrative of the evolution of chemical communication across taxa. From this perspective, the chemosensory dichotomy loses its validity and usefulness. We thus propose the unification of all chemosensory modalities into a single sense, moving toward a synthetic, complex, and interconnected perspective on the gradual processes by which a vast variety of chemicals have become signals that are crucially important to communication among and within cells, organs, and organisms in a wide variety of environmental conditions.

Science is addressing global societal challenges, and due to limitations in research financing, scientists are turning to the public at large to jointly tackle specific environmental issues. Citizens are therefore increasingly involved in monitoring programs, appointed as citizen scientists with potential to delivering key data at near to no cost to address environmental challenges, therein fostering scientific knowledge and advising policy- and decision-makers. One of the first and most successful examples of marine citizen science in the Mediterranean is represented by the integrative and collaborative implementation of several jellyfish-spotting campaigns in Italy, Spain, Malta, and Tunisia starting in 2009. Altogether, in terms of time coverage, geographic extent, and number of citizen records, these represent the most effective marine citizen science campaigns thus far implemented in the Mediterranean Sea. Here, we analyzed a collective database merging records over the above four countries, featuring more than 100,000 records containing almost 25,000 observations of jellyfish specimens collected over a period of 3 to 7 years (from 2009 to 2015) by citizen scientists participating in any of the national citizen science programs included in this analysis. Such a wide citizen science exercise demonstrates a valuable and cost-effective tool to understanding ecological drivers of jellyfish proliferation over the Western and Central Mediterranean basins, as well as a powerful contribution to developing tailored adaptation and management strategies; mitigating jellyfish impacts on human activities in coastal zones; and supporting implementation of marine spatial planning, Blue Growth, and conservation strategies

Global change is striking harder and faster in the Mediterranean Sea than elsewhere, where high levels of human pressure and proneness to climate change interact in mod- ifying the structure and disrupting regulative mechanisms of marine ecosystems. Rocky reefs are particularly exposed to such environmental changes with ongoing trends of degradation being impressive. Due to the variety of habitat types and associated marine biodiversity, rocky reefs are critical for the functioning of marine ecosystems, and their decline could profoundly affect the provision of essential goods and services which human populations in coastal areas rely upon. Here, we provide an up-to-date overview of the status of rocky reefs, trends in human-driven changes undermining their integrity, and current and upcoming management and conservation strategies, attempting a pro- jection on what could be the future of this essential component of Mediterranean marine ecosystems.

Navigating the Future is a publication series produced by the European Marine Board providing future perspectives on marine science and technology in Europe. Navigating the Future V (NFV) highlights new knowledge obtained since Navigating the Future IV1 (2013). It is set within the framework of the 2015 Paris Agreement2 and builds on the scientific basis and recommendations of the IPCC reports3. NFV gives recommendations on the science required during the next decade to deliver the ocean we need to support a sustainable future. This will be important for the United Nations Decade of Ocean Science for Sustainable Development4 (2021 – 2030), the implementation of the UN Sustainable Development Goals5 and the European Commission’s next framework programme, Horizon Europe6 (2021 - 2027). There is a growing need to strengthen the links between marine science, society and policy since we cannot properly manage what we do not know. In recent years, the ocean and seas have received new prominence in international agendas. To secure a safe planet a priority is the management of the ocean as a “common good for humanity”, which requires smarter observations to assess of the state of the ocean and predictions about how it may change in the future. The ocean is a three-dimensional space that needs to be managed over time (thus four-dimensional), and there is a need for management and conservation practices that integrate the structure and function of marine ecosystems into these four dimensions (Chapter 2). This includes understanding the dynamic spatial and temporal interplay between ocean physics, chemistry and biology. Multiple stressors including climate change, pollution and over-fishing affect the ocean and we need to better understand and predict their interactions and identify tipping points to decide on management priorities (Chapter 3). This should integrate our understanding of land-ocean-atmosphere processes and approaches to reducing impacts. An improved sci

Maritime economy, ecosystem-based management and climate change adaptation and mitigation raise emerging needs on coastal ocean and biological observations. Integrated ocean observing aims at optimizing sampling strategies and cost-efficiency, sharing data and best practices, and maximizing the value of the observations for multiple purposes. Recently developed cost-effective, near real time technology such as gliders, radars, ferrybox, and shallow water Argo floats, should be used operationally to generate operational coastal sea observations and analysis. Furthermore, value of disparate coastal ocean observations can be unlocked with multi-dimensional integration on fitness-for-the-purpose, parameter and instrumental. Integration of operational monitoring with offline monitoring programs, such as those for research, ecosystem-based management and commercial purposes, is necessary to fill the gaps. Such integration should lead to a system of networks which can deliver data for all kinds of purposes. Detailed integration activities are identified which should enhance the coastal ocean and biological observing capacity. Ultimately a program is required which integrates physical, biogeochemical and biological observation of the ocean, from coastal to deep-sea environments, bringing together global, regional, and local observation efforts.

Politica e diritto sembrano non essersi ancora del tutto accorte dello stato di emergenza ecologicain cui viviamo, sotto minaccia di estinzione come specie, che gli ecologisti ormai da tempo con forza denunciano. Scienza e diritto in questo campo faticano a dialogare. Il modello di governance ambientale cui gli ordinamenti internazionale e nazionali si ispirano è quello dello sviluppo sostenibile, del principio di precauzione e della limitazione del danno secondo gli standard tecnologici vigenti. Gli ecologisti ne segnalano le insufficienze. Un approccio ai problemi ambientali di tipo interdisciplinare e olistico è l'unica via per rendere veramente possibili un cambio di rotta. I contributi qui raccolti, presentati al convegno dal titolo omonimo svoltosi a Ravenna presso la Scuola di Giurisprudenza il 9 e 10 marzo 2017, rappresentano un primo tentativo di dialogo interdisciplinare alla ricerca di un nuovo paradigma giuridico di governo dell'ecosistema.

Politica e diritto sembrano non essersi ancora del tutto accorte dello stato di emergenza ecologicain cui viviamo, sotto minaccia di estinzione come specie, che gli ecologisti ormai da tempo con forza denunciano. Scienza e diritto in questo campo faticano a dialogare. Il modello di governance ambientale cui gli ordinamenti internazionale e nazionali si ispirano è quello dello sviluppo sostenibile, del principio di precauzione e della limitazione del danno secondo gli standard tecnologici vigenti. Gli ecologisti ne segnalano le insufficienze. Un approccio ai problemi ambientali di tipo interdisciplinare e olistico è l'unica via per rendere veramente possibili un cambio di rotta. I contributi qui raccolti, presentati al convegno dal titolo omonimo svoltosi a Ravenna presso la Scuola di Giurisprudenza il 9 e 10 marzo 2017, rappresentano un primo tentativo di dialogo interdisciplinare alla ricerca di un nuovo paradigma giuridico di governo dell'ecosistema.

Aurelia spp. are cosmopolitan scyphozoan species and probably the most studied jellyfish in the world. They inhabit nearshore waters, especially closed basins, such as coastal embayments, fjords and estuaries, occupying a great variety of habitats worldwide. Recent studies have addressed the biogeography of the genus Aurelia and reported that it constitutes a speciescomplex embracing numerous locally adapted species. The Mediterranean Sea is a hotspot of biodiversity threatened by climate change, which is expected to have a significant influence on the biodiversity and biogeography of marine populations. Here we compiled a comprehensive data set on Aurelia spp. occurrence in the Mediterranean Sea and assessed the thermal niches as well as the phenology of the various populations. Our results indicate that the species biogeography is restricted to temperate areas of the Mediterranean basin, whereas the seasonal pattern generally displayed an unimodal peak that occurs earlier in warmer systems. Our results highlight that the thermal niche of the species, where the bulk of the population (90%) is present, shows a temperature window from 12 to 20°C, although it is further constrained when accounting only for the northern populations of the western and Adriatic basins. Hence, while global warming has been claimed as one of the most important triggers for jellyfish outbreaks, the projected temperature increase of the Mediterranean Sea warns on the shrinking of favorable environmental conditions for the species with the concomitant risk of its potential decline and perhaps extinction in the Mediterranean Sea.

This volume contains the main results of the EC FP7 “The Ocean of Tomorrow” Project CoCoNet, divided in two sections: 1) a set of guidelines to design networks of Marine Protected Areas in the Mediterranean and the Black Seas; 2) a smart wind chart that will allow evaluating the possibility of installing Offshore Wind Farms in both seas. The concept of Cells of Ecosystem Functioning, based on connectivity, is introduced to define natural units of management and conservation. The definition of Good Environmental Status, as defined in the Marine Strategy Framework Directive, is fully embraced to set the objectives of the project, by adopting a holistic approach that integrates a full set of disciplines, ranging from physics to bio-ecology, economics, engineering and many sub-disciplines. The CoCoNet Consortium involved scientist sfrom 22 states, based in Africa, Asia, and Europe, contributing to build a coherent scientific community.

Ecological systems depend on both constraints and historical contingencies, both of which shape their present observable system state. In contrast to ahistorical systems, which are governed solely by constraints (i.e. laws), historical systems and their dynamics can be understood only if properly described, in the course of time. Describing these dynamics and understanding long-term variability can be seen as the mission of long time series measuring not only simple abiotic features but also complex biological variables, such as species diversity and abundances, allowing deep insights in the functioning of food webs and ecosystems in general. Long time-series are irreplaceable for understanding change, and cruicially inherent system variability and thus envisaging future scenarios. This nonewithstanding, current policies in funding and evaluating scientific research discourage the maintenance of long termseries, despite a clear need for long-term strategies to cope with climate change. Timeseries are cruicial for a pursuit of the much invoked Ecosystem Approach and to the passage from simple monitoring programmes large-scale and long-term Earth observatories – thus promoting a better understanding of the causes and effects of change in ecosystems. The few ongoing long timeseries in European waters must be integrated and networked so as to facilitate the formation of nodes of a series of observatories which, together, should allow the long-term management of the features and characteristics of European waters. Human capacity building in this region of expertise and a stronger societal involvement are also urgently needed, since the expertise in recognizing and describing species and therefore recording them reliably in the context of timeseries is rapidly vanishing from the European Scientific community.

Ecological systems depend on both constraints and historical contingencies, both of which shape their present observable system state. In contrast to ahistorical systems, which are governed solely by constraints (i.e. laws), historical systems and their dynamics can be understood only if properly described, in the course of time. Describing these dynamics and understanding long-term variability can be seen as the mission of long time series measuring not only simple abiotic features but also complex biological variables, such as species diversity and abundances, allowing deep insights in the functioning of food webs and ecosystems in general. Long time-series are irreplaceable for understanding change, and cruicially inherent system variability and thus envisaging future scenarios. This nonewithstanding, current policies in funding and evaluating scientific research discourage the maintenance of long termseries, despite a clear need for long-term strategies to cope with climate change. Timeseries are cruicial for a pursuit of the much invoked Ecosystem Approach and to the passage from simple monitoring programmes large-scale and long-term Earth observatories – thus promoting a better understanding of the causes and effects of change in ecosystems. The few ongoing long timeseries in European waters must be integrated and networked so as to facilitate the formation of nodes of a series of observatories which, together, should allow the long-term management of the features and characteristics of European waters. Human capacity building in this region of expertise and a stronger societal involvement are also urgently needed, since the expertise in recognizing and describing species and therefore recording them reliably in the context of timeseries is rapidly vanishing from the European Scientific community.

Jellyfish interactions with human activities are manifold, but gelatinous blooms have always a negative feel to most people. Much research effort is currently devoted to addressing jellyfish population dynamics and the development of forecasting and mitigation tools. However, the lack of long-term and spatial-wide data series represents a key impediment. In the framework of the Med-Jellyrisk Project (www.jellyrisk.eu), a Citizen Science approach is sustaining a prolonged database on Mediterranean jellyfish records to support the development of mitigation tools, e.g. forecasting or risk maps. Several initiatives are required for promoting engagement and interaction with local communities, validating the data, and improving the observation network both in the amount and the quality of observations. As a case study, we present here the most important achievements obtained in the Catalan coast (Spain), together with a general overview of other national initiatives in the Mediterranean Sea and in the rest of the world

Jellyfish outbreaks are increasingly viewed as a deterministic response to escalating levels of environmental degradation and climate extremes. However, a comprehensive understanding of the influence of deterministic drivers and stochastic environmental variations favouring population renewal processes has remained elusive. This study quantifies the deterministic and stochastic components of environmental change that lead to outbreaks of the jellyfish Pelagia noctiluca in the Mediterranen Sea. Using data of jellyfish abundance collected at 241 sites along the Catalan coast from 2007 to 2010 we: (1) tested hypotheses about the influence of time-varying and spatial predictors of jellyfish outbreaks; (2) evaluated the relative importance of stochastic vs. deterministic forcing of outbreaks through the environmental bootstrap method; and (3) quantified return times of extreme events. Outbreaks were common in May and June and less likely in other summer months, which resulted in a negative relationship between outbreaks and SST. Cross- and along-shore advection by geostrophic flow were important concentrating forces of jellyfish, but most outbreaks occurred in the proximity of two canyons in the northern part of the study area. This result supported the recent hypothesis that canyons can funnel P. noctiluca blooms towards shore during upwelling. This can be a general, yet unappreciated mechanism leading to outbreaks of holoplanktonic jellyfish species. The environmental bootstrap indicated that stochastic environmental fluctuations have negligible effects on return times of outbreaks. Our analysis emphasized the importance of deterministic processes leading to jellyfish outbreaks compared to the stochastic component of environmental variation. A better understanding of how environmental drivers affect demographic and population processes in jellyfish species will increase the ability to anticipate jellyfish outbreaks in the future

Genetic 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.

Genetic 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.

In recent years, jellyfish blooms have attracted considerable scientific interest for their potential impacts on human activities and ecosystem functioning, with much attention paid to jellyfish as predators and to gelatinous biomass as a carbon sink. Other than qualitative data and observations, few studies have quantified direct predation of fish on jellyfish to clarify whether they may represent a seasonally abundant food source. Here we estimate predation frequency by the commercially valuable Mediterranean bogue, Boops boops on the mauve stinger jellyfish, Pelagia noctiluca, in the Strait of Messina (NE Sicily). A total of 1054 jellyfish were sampled throughout one year to quantify predation by B. boops from bite marks on partially eaten jellyfish and energy density of the jellyfish. Predation by B. boops in summer was almost twice that in winter, and they selectively fed according to medusa gender and body part. Calorimetric analysis and biochemical composition showed that female jellyfish gonads had significantly higher energy content than male gonads due to more lipids and that gonads had six-fold higher energy content than the somatic tissues due to higher lipid and protein concentrations. Energetically, jellyfish gonads represent a highly rewarding food source, largely available to B. boops throughout spring and summer. During the remainder of the year, when gonads were not very evident, fish predation switched towards lessselective foraging on the somatic gelatinous biomass. P. noctiluca, the most abundant jellyfish species in the Mediterranean Sea and a key planktonic predator, may represent not only a nuisance for human leisure activities and a source of mortality for fish eggs and larvae, but also an important resource for fish species of commercial value, such as B. boops. © 2014 Milisenda et al.

Over recent decades, man’s expanding influence on the oceans has begun to cause change in some regions, including in the Mediterranean Sea. New proliferations of jellyfi sh may be occurring in the Mediterranean Sea, possibly in response to the cumulative effects of some of these anthropogenic impacts. In the Mediterranean Sea, many of these “proliferation events” are due to Pelagia noctiluca, an oceanic scyphozoan that has become very abundant along the coasts. Pelagia noctiluca is usually considered to be the most important jellyfi sh species in the Mediterranean Sea due to its widespread distribution, abundance, and ecological role and also because of its negative interaction with humans. Climatic conditions that favor enhanced reproduction by P. noctiluca and probably also determine optimal conditions for the formation of blooms are characterized by mild winters, low rainfall, high temperature, and high-atmospheric pressure. The Medusa Project in Catalonia aims to understand the spatiotemporal dynamics of the jellyfi sh populations in the NW Mediterranean Sea by undertaking daily sampling during summer (May to September) of 243 beaches, covering more than 500 km of coast. Data on beach strandings along the Spanish Catalan coast revealed that jellyfi sh occur in greatest concentrations along the northern Catalan coast and on beaches located close to marine canyons. The arrival of P. noctiluca to the coast depends fi rstly on the offshore production of jellyfi sh. Oceanographic structures like fronts, which enhance and maintain high levels of biological production and provide ideal conditions for feeding, growth, and reproduction of the jellyfi sh are present in the NW Mediterranean. The weakening of the front results in large numbers of P. noctiluca being driven into the coast by southeast winds. In the NW Mediterranean Sea P. noctiluca exert top-down control over a variety of prey including fish eggs and possibly the invasive ctenophore Mnemiopsis leidyi. P. noct

The genus Gastroblasta was proposed by Keller in 1883 for a campanulariid medusa from the Red Sea, G. timida, with round umbrella, multiple radial canals and multiple manubria. A second species, G. raffaelei, with elliptic umbrella, multiple manubria and radial canals, and a great tendency to fission, was subsequently described from the Mediterranean Sea by Lang in 1886. A third species with multiple manubria was described by Mayer in 1900 from Tortugas: Multioralis ovalis (currently ascribed to Gastroblasta). The complete life cycle of a species of Gastroblasta, whose polyp stage was collected inside sponges from the Ligurian Sea and the Ionian and Adriatic Seas, is described. The first stage of medusa development is a typical Clytia with four radial canals and four tentacles, then the medusa becomes similar to G. ovale, to subsequently acquire the typical morphology of G. raffaelei. The species G. timida and G. raffaelei are considered as valid representatives of the genus, sharing the characters of multiple manubria and radial canals. The medusa of G. ovale has a diagonal canal system, instead of multiple radial canals, sharing with Gastroblasta the presence of multiple manubria only: it is proposed to resurrect the genus Multioralis to accommodate it., SCOPUS: re.j, info:eu-repo/semantics/published

The genus Gastroblasta was proposed by Keller in 1883 for a campanulariid medusa from the Red Sea, G. timida, with round umbrella, multiple radial canals and multiple manubria. A second species, G. raffaelei, with elliptic umbrella, multiple manubria and radial canals, and a great tendency to fission, was subsequently described from the Mediterranean Sea by Lang in 1886. A third species with multiple manubria was described by Mayer in 1900 from Tortugas: Multioralis ovalis (currently ascribed to Gastroblasta). The complete life cycle of a species of Gastroblasta, whose polyp stage was collected inside sponges from the Ligurian Sea and the Ionian and Adriatic Seas, is described. The first stage of medusa development is a typical Clytia with four radial canals and four tentacles, then the medusa becomes similar to G. ovale, to subsequently acquire the typical morphology of G. raffaelei. The species G. timida and G. raffaelei are considered as valid representatives of the genus, sharing the characters of multiple manubria and radial canals. The medusa of G. ovale has a diagonal canal system, instead of multiple radial canals, sharing with Gastroblasta the presence of multiple manubria only: it is proposed to resurrect the genus Multioralis to accommodate it., SCOPUS: re.j, info:eu-repo/semantics/published

The superclass Hydrozoa of the phylum Cnidaria comprises 3,702 species currently regarded as valid, ascribed to three heterogeneous classes. The 134 species of the class Automedusa have simple life cycles with medusae and no polyp stage, and are divided into three subclasses: Actinulidae, Narcomedusae, Trachymedusae. The 3,567 species of the class Hydroidomedusa have complex life cycles with polyps producing medusae through a medusary nodule, and are divided into five subclasses: Anthomedusae, Laingiomedusae, Leptomedusae, Limnomedusae, Siphonophorae. The single species of the class Polypodiozoa has a complex life cycle, involving endocellular parasitism. Diagnoses and keys are presented for all supraspecific taxa, and lists of included species are given for each genus. The diagnostic characters and character states in the superclass are described. A glossary summarizes definitions of all technical terms referred to in the superclass. References to all original species descriptions are given. Zhangiella nom. nov. pro Platystoma Zhang, 1982, non Meigen, 1803 Pseudosolanderiidae Bouillon & Gravier-Bonnet, fam. nov.

This study provides a systematic account of the hydrozoan species collected up to now in the Mediterranean Sea. All species are described, illustrated and information on morphology and distribution is given for all of them. This work is the most complete fauna of hydrozoans made in the Mediterranean. The fauna includes planktonic hydromedusae, benthic polyps stages and the siphonophores. The Hydrozoa are taken as an example of inconspicuous taxa whose knowledge has greatly progressed in the last decades due to the scientific research of some specialists in the Mediterranean area. The number of species recorded in the Mediterranean almost doubled in the last thirty years and the number of new records is still increasing. The 457 species recorded in this study represents the 12% of the world known species. The fauna is completed with classification keys anda glossary of terms with the main purpose of facilitating the identification of ali Meditrranean hydrozoan species., SCOPUS: re.j, info:eu-repo/semantics/published

This study provides a systematic account of the hydrozoan species collected up to now in the Mediterranean Sea. All species are described, illustrated and information on morphology and distribution is given for all of them. This work is the most complete fauna of hydrozoans made in the Mediterranean. The fauna includes planktonic hydromedusae, benthic polyps stages and the siphonophores. The Hydrozoa are taken as an example of inconspicuous taxa whose knowledge has greatly progressed in the last decades due to the scientific research of some specialists in the Mediterranean area. The number of species recorded in the Mediterranean almost doubled in the last thirty years and the number of new records is still increasing. The 457 species recorded in this study represents the 12% of the world known species. The fauna is completed with classification keys anda glossary of terms with the main purpose of facilitating the identification of ali Meditrranean hydrozoan species., SCOPUS: re.j, info:eu-repo/semantics/published

[EN] This study provides a systematic account of the hydrozoan species collected up to now in the Mediterranean Sea. All species are described, illustrated and information on morphology and distribution is given for all of them. This work is the most complete fauna of hydrozoans made in the Mediterranean. The fauna includes planktonic hydromedusae, benthic polyps stages and the siphonophores. The Hydrozoa are taken as an example of inconspicuous taxa whose knowledge has greatly progressed in the last decades due to the scientific research of some specialists in the Mediterranean area. The number of species recorded in the Mediterranean almost doubled in the last thirty years and the number of new records is still increasing. The 457 species recorded in this study represent the 12% of the world known species. The fauna is completed with classification keys and a glossary of terms with the main purpose of facilitating the identification of all Meditrranean hydrozoan species, [ES] Este estudio proporciona una relación sistemática de las especies de hidrozoos conocidas hasta la actualidad en el mar Mediterráneo. Se describen e ilustran todas las especies de las cuales se ofrece información sobre su morfología y distribución. Este trabajo es la fauna mas completa de hidrozoos hecha en el Mediterráneo. Esta fauna incluye las hidromedusas planctónicas, los estadios bentónicos de pólipos y los sifonóforos. Los Hydrozoa se han tomado como un ejemplo de taxones inconspicuos cuyo conocimiento ha progresado enormemente durante las últimas décadas gracias a la investigación de algunos especialistas en el area mediterránea. El número de especies citadas en el Mediterráneo se ha casi doblado en los últimos treinta años y el número de nuevos registros sigue incrementándose. Las 457 especies referenciadas en este estudio representan el 12% del total mundial de especies. La fauna se complementa con claves de clasificación y un glosario de términos con el propósito de facilitar la identificación de todas las especies de hidrozoos del Mediterráneo

The genera Zanclea, Halocoryne and Zanclella are surveyed, with description of all known species, including eight new ones of Zanclea (Z. bomala, Z. divergens, Z. fanella, Z. giancarloi, Z. medusopolypata, Z. retractilis, Z. gilii, Z. hirohitoi), two new species of Halocoryne (H. frasca, H. pirainoid), and two new ones of Zanclella (Z. diabolica, Z. glomboides). For most species, the description covers the whole life cycle. The hydroids of this group can be symbiotic with either bryozoans, bivalves, or corals and only few species are not substrate-specialist. Symbiotic relationships led to polymorphism and colony integration with the hosts. The morphologies of hydroid and medusa stages are often not consistent, so that species with very derived hydroids have non-derived medusae (e.g. Halocoryne pirainoid), or species with very derived medusae have non-derived hydroids (e.g. Zanclella diabolica). The architecture of the newly released medusae of Zanclella is exceptional due to a sharp compression of the exumbrella and of the presence of just two radial canals. A phylogenetic scenario is suggested, in spite of the inconsistencies in the rates of change in the two main stages of the cycle., SCOPUS: ar.j, info:eu-repo/semantics/published

The genera Zanclea, Halocoryne and Zanclella are surveyed, with description of all known species, including eight new ones of Zanclea (Z. bomala, Z. divergens, Z. fanella, Z. giancarloi, Z. medusopolypata, Z. retractilis, Z. gilii, Z. hirohitoi), two new species of Halocoryne (H. frasca, H. pirainoid), and two new ones of Zanclella (Z. diabolica, Z. glomboides). For most species, the description covers the whole life cycle. The hydroids of this group can be symbiotic with either bryozoans, bivalves, or corals and only few species are not substrate-specialist. Symbiotic relationships led to polymorphism and colony integration with the hosts. The morphologies of hydroid and medusa stages are often not consistent, so that species with very derived hydroids have non-derived medusae (e.g. Halocoryne pirainoid), or species with very derived medusae have non-derived hydroids (e.g. Zanclella diabolica). The architecture of the newly released medusae of Zanclella is exceptional due to a sharp compression of the exumbrella and of the presence of just two radial canals. A phylogenetic scenario is suggested, in spite of the inconsistencies in the rates of change in the two main stages of the cycle., SCOPUS: ar.j, info:eu-repo/semantics/published

The ecological importance of resting stages in shallow waters is well known, but their presence in the deep sea is practically unrecorded, Samples of sinking particles were collected from April 1993 to May 1994 in and around the Foix Canyon (northwest Mediterranean Sea) using PPS3 sediment traps located between -600 m and -1180 m, Dead and viable organisms were collected, and inorganic empty shells constituted most of the biologically-derived malter, Resting stages, considered as POM, had a flux ofup to 70000 items m-2 d-1, They were the second most abundant fraction of total POM after tintinnids (mainly represented by empty, chitinous loricas), and first of the viable POM fraction, Most remained unidentified, but 58 morphotypes were referable to coastal species of Dinophyta, Tintinnina and Calanoida, Resting stages were rare in samples collected from the open slope adjacent to the canyon, These preliminary data suggest an important role of submarine canyons in concentrating POM and transferring it from shallow to deep-sea habitats, Due to their resistance to degradation processes, resting stages are probably the only POM component that can retum to shallow areas by upwelling currents occurring in the canyon

This volume represents the fourth in a series 1, 2, 3 published following workshops of the international Hydrozoan Society. This volume is composed of some of the presentations from that meeting. The Hydrozoan Society workshops provide a unique opportunity for those of us who study hydroids and hydromedusae, usually in comparative isolation, to really get to know each other at a personal level and to share ideas and promote future collaborations between people of similar interests, even if we come from different disciplines [...]

The hydromedusan subumbrellar muscle tissues originate from a mass of endo- and ectoderm derived cells proliferating inwardly. This mass of cells, called entocodon, is separated by the ecto-and endoderm through a layer of extracellular matrix, thus forming a locally triploblastic arrangement of tissues. By cavitation and differentiation, the entocodon gives rise to the striated and smooth muscle layers of the subumbrella. The structure of the striated muscle is histologically identical to that described for triploblasts, where striated muscle is mainly mesodermic. Together with the mode of development, this suggests that not all Cnidaria are diploblastic and that the subumbrellar cavity is a coelom-like structure. The subumbrellar cavity is formed late in ontogeny, whereas the coelom in higher animals is normally formed during embryonic development. Instead of remaining closed, the subumbrella becomes open, with the muscular mesothelium in contact with the environment. This view of cnidarian structures can be pushed further while considering the regulation of modularity and metamery. The occurrence of homeotic genes in cnidarians and other 'lower' animals shows that the specification of body architecture has a common molecular ground throughout the animal kingdom. It is suggested that the expression of homeotic genes while specifying a given architecture might be regulated by iteration of their activity, leading to 'low' modular organisms and to 'higher' metameric ones. Replicated parts as modules and metameres might be analogous, but the affinity in their molecular specification (and possibly regulation) might indicate homology. The number of resemblances between cnidarians and 'higher' metazoa suggests that this phylum might be a centre of metazoan radiation, having structures which represent the living premises of the main steps of animal evolution., SCOPUS: ar.j, info:eu-repo/semantics/published

The hydromedusan subumbrellar muscle tissues originate from a mass of endo- and ectoderm derived cells proliferating inwardly. This mass of cells, called entocodon, is separated by the ecto-and endoderm through a layer of extracellular matrix, thus forming a locally triploblastic arrangement of tissues. By cavitation and differentiation, the entocodon gives rise to the striated and smooth muscle layers of the subumbrella. The structure of the striated muscle is histologically identical to that described for triploblasts, where striated muscle is mainly mesodermic. Together with the mode of development, this suggests that not all Cnidaria are diploblastic and that the subumbrellar cavity is a coelom-like structure. The subumbrellar cavity is formed late in ontogeny, whereas the coelom in higher animals is normally formed during embryonic development. Instead of remaining closed, the subumbrella becomes open, with the muscular mesothelium in contact with the environment. This view of cnidarian structures can be pushed further while considering the regulation of modularity and metamery. The occurrence of homeotic genes in cnidarians and other 'lower' animals shows that the specification of body architecture has a common molecular ground throughout the animal kingdom. It is suggested that the expression of homeotic genes while specifying a given architecture might be regulated by iteration of their activity, leading to 'low' modular organisms and to 'higher' metameric ones. Replicated parts as modules and metameres might be analogous, but the affinity in their molecular specification (and possibly regulation) might indicate homology. The number of resemblances between cnidarians and 'higher' metazoa suggests that this phylum might be a centre of metazoan radiation, having structures which represent the living premises of the main steps of animal evolution., SCOPUS: ar.j, info:eu-repo/semantics/published

Codonorchis octaedrus is recorded for the first time since its discovery by Haeckel in 1879. A hydroid colony collected in a cave of the Apulian Coast (between the Ionian and the Adriatic Seas) produced several medusae which have been reared to maturity. This is the first complete description of the species, which was previously considered as doubtful, as was the genus Codonorchis. The diagnostic features for the genus are: hydroid small, naked, sessile, with a single row of few tentacles, gonophores on hydrorhiza, medusa with apical projection with apical process from the manubrium, perradial, interradial and adradial ocellate bulbs, two perradial tentacles, horseshoe-shaped interradial gonads, small mesenteries. The list of Mediterranean hydroidomedusae is updated with the new (or overlooked) records since the last published list (1993). The increase in species number is great (about 10%), showing that the knowledge of biodiversity of even a well-studied sea as the Mediterranean is far from being complete., SCOPUS: ar.j, info:eu-repo/semantics/published

Three species of hydroids referable to the genus Zanclea are recorded from the Apulian waters (Ionian Sea). Species distinction is based mainly on cnidome, and especially on the morphology and position of macrobasic euryteles: Zanclea sessilis growing on bryozoans, with apotrichous macrobasic euryteles with shaft coiled in a horseshoe shape, disposed in a circle around the hypostome, and in the hydrorhiza; Zanclea costata growing on bivalve shells, with holotrichous (?) macrobasic euryteles with a spirally coiled shaft, abundant in the hydrorhiza and rare in the hydranth body; and Zanclea sp. growing on bryozoans, with apotrichous macrobasic euryteles of two sizes, both with shaft coiled along the long axis of the capsule, dispersed in the hydranth body and in the hydrorhiza. The hydroids of Zanclea sessilis and Zanclea sp. were reared under identical controlled conditions for more than one year, but their morphological features remained unchanged and they both produced medusae. The medusae of Zanclea sessilis were reared to maturity, those of Zanclea sp. just to a young age. The main difference between the medusae was the consistent presence of an enlargement of the middle part of radial canals in Zanclea sessilis (from newly released to adult specimens), a feature lacking in Zanclea sp. It is confirmed that, as already suggested by several authors, cnidome is a reliable feature for species identification of Zanclea hydroids, but medusa identification remains more problematic. In spite of the widespread claim that Zanclea is represented world-wide by a single species, it is here demonstrated that the genus comprises at least three species in the Mediterranean., SCOPUS: ar.j, info:eu-repo/semantics/published

Three species of hydroids referable to the genus Zanclea are recorded from the Apulian waters (Ionian Sea). Species distinction is based mainly on cnidome, and especially on the morphology and position of macrobasic euryteles: Zanclea sessilis growing on bryozoans, with apotrichous macrobasic euryteles with shaft coiled in a horseshoe shape, disposed in a circle around the hypostome, and in the hydrorhiza; Zanclea costata growing on bivalve shells, with holotrichous (?) macrobasic euryteles with a spirally coiled shaft, abundant in the hydrorhiza and rare in the hydranth body; and Zanclea sp. growing on bryozoans, with apotrichous macrobasic euryteles of two sizes, both with shaft coiled along the long axis of the capsule, dispersed in the hydranth body and in the hydrorhiza. The hydroids of Zanclea sessilis and Zanclea sp. were reared under identical controlled conditions for more than one year, but their morphological features remained unchanged and they both produced medusae. The medusae of Zanclea sessilis were reared to maturity, those of Zanclea sp. just to a young age. The main difference between the medusae was the consistent presence of an enlargement of the middle part of radial canals in Zanclea sessilis (from newly released to adult specimens), a feature lacking in Zanclea sp. It is confirmed that, as already suggested by several authors, cnidome is a reliable feature for species identification of Zanclea hydroids, but medusa identification remains more problematic. In spite of the widespread claim that Zanclea is represented world-wide by a single species, it is here demonstrated that the genus comprises at least three species in the Mediterranean., SCOPUS: ar.j, info:eu-repo/semantics/published

info:eu-repo/semantics/published

info:eu-repo/semantics/published

Neurotransmission in Cnidarians is known to occur mainly by peptidergic neuronal pathways; the role of cholinergic neurotransmission, that in other animals this involves both neurotransmission and developmental regulation, has never been shown with certainty. This histochemical-immunohistochemical study was performed, in different developmental stages of some hydroidomedusan species (characterized by different reproductive and developmental patterns) to investigate the presence and distribution of cholinesterase (ChE) activity, acetylcholine receptors, biogenic amines, and molecules immunologically related to secretory peptides (FMRF amide and VIP). The results showed that ChE (revealed by all the kinds of activities: AChE, PrChE, BuChE) is mainly present in developing or 'juvenile' structures. Biogenic amines are revealed by aldehyde-induced fluorescence at every stage studied, while peptide-like immunoreactivities are mainly present in differentiated structures. These findings support the hypothesis that all the chemical messengers here investigated arose very early in evolution, although, in some cases, with different functions. For most of the investigated species, similarities in the distribution pattern of markers generally reflect similarities in life cycle, rather than phylogenetic affinities. © 1994., SCOPUS: ar.j, info:eu-repo/semantics/published

Neurotransmission in Cnidarians is known to occur mainly by peptidergic neuronal pathways; the role of cholinergic neurotransmission, that in other animals this involves both neurotransmission and developmental regulation, has never been shown with certainty. This histochemical-immunohistochemical study was performed, in different developmental stages of some hydroidomedusan species (characterized by different reproductive and developmental patterns) to investigate the presence and distribution of cholinesterase (ChE) activity, acetylcholine receptors, biogenic amines, and molecules immunologically related to secretory peptides (FMRF amide and VIP). The results showed that ChE (revealed by all the kinds of activities: AChE, PrChE, BuChE) is mainly present in developing or 'juvenile' structures. Biogenic amines are revealed by aldehyde-induced fluorescence at every stage studied, while peptide-like immunoreactivities are mainly present in differentiated structures. These findings support the hypothesis that all the chemical messengers here investigated arose very early in evolution, although, in some cases, with different functions. For most of the investigated species, similarities in the distribution pattern of markers generally reflect similarities in life cycle, rather than phylogenetic affinities. © 1994., SCOPUS: ar.j, info:eu-repo/semantics/published

The distribution of the 346 hydromedusan species hitherto recorded from the Mediterranean is considered, dividing the species into zoogeographical groups. The consequences for dispersal due to possession or lack of a medusa stage in the life cycle are discussed, and related to actual known distributions. There is contradictory evidence for an influence of life cycle patterns on species distribution. The Mediterranean hydromedusan fauna is composed of 19.5% endemic species. Their origin is debatable. The majority of the remaining Mediterranean species is present in the Atlantic, with various world distributions, and could have entered the Mediterranean from Gibraltar after the Messinian crisis. Only 8.0% of the fauna is classified as Indo-Pacific, the species being mainly restricted to the eastern basin, some of which have presumably migrated from the Red Sea via the Suez Canal, being then classifiable as Lessepsian migrants. The importance of historical and climatic factors in determining the composition of the Mediterranean fauna of hydromedusae is discussed. © 1993 The Linnean Society of London., SCOPUS: ar.j, info:eu-repo/semantics/published

The distribution of the 346 hydromedusan species hitherto recorded from the Mediterranean is considered, dividing the species into zoogeographical groups. The consequences for dispersal due to possession or lack of a medusa stage in the life cycle are discussed, and related to actual known distributions. There is contradictory evidence for an influence of life cycle patterns on species distribution. The Mediterranean hydromedusan fauna is composed of 19.5% endemic species. Their origin is debatable. The majority of the remaining Mediterranean species is present in the Atlantic, with various world distributions, and could have entered the Mediterranean from Gibraltar after the Messinian crisis. Only 8.0% of the fauna is classified as Indo-Pacific, the species being mainly restricted to the eastern basin, some of which have presumably migrated from the Red Sea via the Suez Canal, being then classifiable as Lessepsian migrants. The importance of historical and climatic factors in determining the composition of the Mediterranean fauna of hydromedusae is discussed. © 1993 The Linnean Society of London., SCOPUS: ar.j, info:eu-repo/semantics/published

info:eu-repo/semantics/published

info:eu-repo/semantics/published

info:eu-repo/semantics/published

info:eu-repo/semantics/published

info:eu-repo/semantics/published

info:eu-repo/semantics/published