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Porifera are considered key components of benthic communities, being typical inhabitants of both shallow and deep waters, from the mesolittoral to the bathyal zone. Although sponges are one of the most common organisms in Western Mediterranean ecosystems, in many areas the knowledge on this taxon is still very limited. In the current study, we aim to analyse and compare the sponge communities characterising the hard bottoms of two islands, Montecristo and Giglio, belonging to the Tuscan Archipelago National Park (TANP, Italy), in relation to a bathymetric gradient. A total of 340 samples were collected, 13 orders and 48 species (46 Demospongiae and 2 Calcarea) identified, with Chondrosia reniformis representing the most recorded species, being found at all sites at almost all depths. Depth was the only significant factor in the observed pattern, while the sponge community is shared between the two Islands. In addition, our data were analysed together with data available in the literature on sponges of the Tuscan Archipelago, to assess the sampling effort. Among all the Islands of the Archipelago, Giglio and Montecristo showed the higher mean species diversity. Nonetheless, the sampling effort resulted not sufficient for each Island and future studies targeting Porifera are needed. Our work is the first summarising the sponge diversity of the entire Tuscan Archipelago, and one of the few focussing entirely on the sponge fauna. These results provide new important information on the area of the TANP, aimed to become a future Marine Protected Area, adding new records, and highlighting the high diversity of a poorly known area.

Mesophotic habitats, hosting benthic assemblages totally unknown and unexpected in the early 2000s, are attracting an increasing interest from scientists. Realizing that many long living and habitat forming species are playing a unique pocket of biodiversity in the frame of climate crisis, it is important to recognize the potential of the mesophotic zone in conservation strategies. The mesophotic zone is characterized by environmental factors generally more stable than the shallow counterpart; therefore, it represents a refuge habitat to preserve species that, in shallow waters, may be involved in bleaching events, massive mortalities or other pathologies generally triggered by thermal anomalies. The definition of the mesophotic zone in the temperate seas is confused, creating possible misunderstandings and problems not only from a scientific point of view but also in communication and outreach strategies. Here, we review the scientific literature to build the best definition possible based on the maximum consensus coming from papers analysis. Moreover, the key roles of mesophotic habitats, including ecosystem engineers as animal forests, have been schematized to enhance the perception of the potential risks we are running in case of damage or loss of these habitats.

Stylasterids belong to one of the few calcifying hydroid families that are commonly found in shallow tropical coral reefs. Although these corals are accurately described from a taxonomic point of view, information about their ecology is scarce. Distichopora violacea is one of the most common stylasterids of the Indo-Pacific region; however, no information is yet available on its distribution and abundance. To fill this gap data we gathered data during three scientific expeditions on four Maldivian atolls. In each atoll investigations were carried out at three depths, both in the ocean and in the lagoon reef, to examine differences in colony density and distribution. Distichopora violacea was observed in all the studied atolls; however, its distribution and density were not homogeneous among them. This species was more abundant in the ocean reefs than in the lagoon ones, suggesting a strong influence of water movement. Moreover, we found a high variability in colony density in the eastern ocean reefs that was tentatively attributed to a different topography of the reef: colonies were more abundant on the gentle slopes of Malè atolls than on the steep reefs of Felidhoo. Oceanographic features, mainly due to the seasonal monsoons, are likely to interact with the biological requirements of the species in determining the observed asymmetrical geographical distribution. The present investigation provides new insights on the stylasterid D. violacea and, for the first time, quantitative data on its distribution and density that can be useful for conservation and management of this CITES regulated species.

Cnidarians may dominate benthic communities, as in the case of coral reefs that foster biodiversity and provide important ecosystem services. Polyps may feed by predating mesozooplantkon and large motile prey, but many species further obtain autotrophic nutrients from photosymbiosis. Anthropogenic disturbance, such as the rise of seawater temperature and turbidity, can lead to the loss of symbionts, causing bleaching. Prolonged periods of bleaching can induce mortality events over vast areas. Heterotrophy may allow bleached cnidarians to survive for long periods of time. We tested the reinforcement of heterotrophic feeding of bleached polyps of Exaiptasia diaphana fed with both small zooplantkon and large prey, in order to evaluate if heterotrophy allows this species to compensate the reduction of autotrophy. Conversely to expected, heterotrophy was higher in unbleached polyps (+54% mesozooplankton prey and +11% large prey). The increase of heterotrophic intake may not be always used as a strategy to compensate autotrophic depletion in bleached polyps. Such a resilience strategy might be more species-specific than expected., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Microbial communities inhabiting sponges are known to take part in many metabolic pathways, including nutrient cycles, and possibly also in the bioaccumulation of trace elements (TEs). Here, we used high-throughput, Illumina sequencing of 16S rRNA genes to characterize the prokaryotic communities present in the cortex and choanosome, respectively the external and internal body region of Chondrosia reniformis, and in the surrounding seawater. Furthermore, we estimated the total mercury content (THg) in these body regions of the sponge and in the corresponding microbial cell pellets. Fifteen prokaryotic phyla were detected in association with C. reniformis, 13 belonging to the domain Bacteria and two to the Archaea. No significant differences between the prokaryotic community composition of the two regions were found. Three lineages of ammonium-oxidizing organisms (Cenarchaeum symbiosum, Nitrosopumilus maritimus, and Nitrosococcus sp.) co-dominated the prokaryotic community, suggesting ammonium oxidation/nitrification as a key metabolic pathway within the microbiome of C. reniformis. In the sponge fractions, higher THg levels were found in the choanosome compared to the cortex. In contrast, comparable THg levels found in the microbial pellets obtained from both regions were significantly lower than those observed in the corresponding sponge fractions. Our work provides new insights into the prokaryotic communities and TEs distribution in different body parts of a model organism relevant for marine conservation and biotechnology. In this sense, this study paves the way for scientists to deepen the possible application of sponges not only as bioindicators, but also as bioremediation tools of metal polluted environments., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Camilla Roveta reports financial support, administrative support, equipment, drugs, or supplies, and travel were provided by Europe Horizons. Rodrigo Costa reports financial support was provided by Fundação para a Ciência e Tecnologia., (Copyright © 2023 Elsevier GmbH. All rights reserved.)

Traditionally, monitoring approaches to survey marine caves have been constrained by equipment limitations and strict safety protocols. Nowadays, the rise of new approaches opens new possibilities to describe these peculiar ecosystems. The current study aimed to explore the potential of Structure from Motion (SfM) photogrammetry to assess the abundance and spatial distribution of the sessile benthic assemblages inside a semi-submerged marine cave. Additionally, since impacts of recent date mussel Lithophaga lithophaga illegal fishing were recorded, a special emphasis was paid to its distribution and densities. The results of SfM were compared with a more "traditional approach", by simulating photo-quadrats deployments over the produced orthomosaics. A total of 22 sessile taxa were identified, with Porifera representing the dominant taxa within the cave, and L. lithophaga presenting a density of 88.3 holes/m 2 . SfM and photo-quadrats obtained comparable results regarding species richness, percentage cover of identified taxa and most of the seascape metrics, while, in terms of taxa density estimations, photo-quadrats highly overestimated their values. SfM resulted in a suitable non-invasive technique to record marine cave assemblages. Seascape indexes proved to be a comprehensive way to describe the spatial pattern of distribution of benthic organisms, establishing a useful baseline to assess future community shifts., (© 2023. The Author(s).)

Marine beach litter (MBL) represents a serious issue for marine life, coastal ecosystems, human health and several economical activities. The Mediterranean Sea is a semi enclosed basin particularly vulnerable to this problem. Its coasts are threatened by critical anthropogenic pressures that sum up with intensive fishing and shipping, and the slow turnover of its waters. In the last decades, several scientific and participative initiatives have been conducted to study, monitor and clean-up shorelines. These studies were generally characterized by differences in timing and frequency of the surveys, as well as in litter sampling, classification and analysis. This paper presents a systematic review of current literature concerning MBL monitoring strategies along the Mediterranean coasts. Scopus indexed studies are analysed to identify discrepancies and similarities among the applied protocols, understand where current gaps lie, and point out what would be needed to develop a basin-scale efficient monitoring for the Mediterranean Sea., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Litter reduction in the coastal and marine environment represents a major challenge but must be prioritized to preserve biodiversity and ecosystems, as well as the goods and services that humans derive from seas and oceans. This paper reviews the available global scientific literature focusing on marine beach litter and tracks its evolution and trends by combining social network analysis and bibliometrics. The relationships and co-occurrences among authors, countries and keywords retrieved from the Scopus abstract and citation database are presented. A total of 1765 publications are analysed: the majority being journal articles. Results reveal the notable worldwide increase in scientific interest in beach litter in the last decade, as well as its multidisciplinary perspectives. This information could be beneficial for the processes that support the improvement of international efforts for beach litter monitoring, removal, and management activities., (Copyright © 2021. Published by Elsevier Ltd.)

Soft compliant strain gauges are key devices for wearable applications such as body health sensor systems, exoskeletons, or robotics. Other than traditional piezoresistive materials, such as metals and doped semiconductors placed on strain-sensitive microsystems, a class of soft porous materials with exotic mechanical properties, called auxetics, can be employed in strain gauges in order to boost their performance and add functionalities. For strain electronic read-outs, their polymeric structure needs to be made conductive. Herein, we present the fabrication process of an auxetic electrode based on a polymeric nanocomposite. A multiwalled carbon nanotube/polydimethylsiloxane (MWCNT/PDMS) is fabricated on an open-cell polyurethane (PU) auxetic foam and its effective usability as an electrode for strain-gauge sensors is assessed.

The genus Zygophylax is a genus of leptothecate hydroids considerably rich in the number of species in the deep sea. In this study we review five species, Z. africana, Z. crozetensis, Z. infundibulum, Z. millardae and Z. geminocarpa, from southern Africa based on available material from several collections, describing and illustrating materials from type series or additional material. Additionally, we describe Zygophylax naomiae sp. nov. collected in South Africa at a depth of 287 m, distinguished from its congeners by the strong pattern of annulations of the pedicels of the hydrotheca and the nematotheca.

Biofouling is one of the challenges that can strongly affect the finfish farm economy. Although several studies on biofouling in aquaculture have been conducted in the Mediterranean Sea, they focused on specific taxa or were limited to a particular period of sampling. The present study investigated for the first time the development, composition and variation in a biofouling community in a finfish farm with immersion time, season and depth. The results indicate that all these factors influence biofouling succession and recruitment. Moreover, the species that had a crucial role in structuring the community and in the farm cleaning activities were the ascidian Styela plicata and the bivalve Mytilus galloprovincialis . Compared with the literature data, the results highlight the heterogeneity in the composition of the biofouling present in the Mediterranean Sea. Moreover, such knowledge of the biofouling community could provide important information about management efforts and the costs that farmers will face when siting new fish farms.

Vascular grafts are artificial conduits properly designed to substitute a diseased blood vessel. However prosthetic fail can occur without premonitory symptoms. Continuous monitoring of the system can provide useful information not only to extend the graft's life but also to optimize the patient's therapy. In this respect, various techniques have been used, but all of them affect the mechanical properties of the artificial vessel. To overcome these drawbacks, an ultrathin and flexible smart patch based on piezoelectric Aluminum Nitride (AlN) integrated on the extraluminal surface of the prosthesis is presented. The sensor can be conformally wrapped around the external surface of the prosthesis. Its design, mechanical properties and dimensions are properly characterized and optimized in order to maximize performances and to avoid any interference with the graft structure during its activity. The sensorized graft is tested in vitro using a pulsatile recirculating flow system that mimics the physiological and pathological blood flow conditions. In this way, the ability of the device to measure real-time variations of the hemodynamics parameters has been tested. The obtained high sensitivity of 0.012 V Pa -1 m -2 , joint to the inherent biocompatibility and non-toxicity of the used materials, demonstrates that the device can successfully monitor the prosthesis functioning under different conditions, opening new perspectives for real-time vascular graft surveillance.

Stylasteridae is a hydroid family including 29 worldwide-distributed genera, all provided with a calcareous skeleton. They are abundant in shallow and deep waters and represent an important component of marine communities. In the present paper, we studied the evolution of ten morphological characters, currently used in stylasterid taxonomy, using a phylogenetic approach. Our results indicate that stylasterid morphology is highly plastic and that many events of independent evolution and reversion have occurred. Our analysis also allows sketching a possible identikit of the stylasterid ancestor. It had calcareous skeleton, reticulate-granular coenosteal texture, polyps randomly arranged, gastrostyle, and dactylopore spines, while lacking a gastropore lip and dactylostyles. If the ancestor had single or double/multiple chambered gastropore tube is uncertain. These data suggest that the ancestor was similar to the extant genera Cyclohelia and Stellapora. Our investigation is the first attempt to integrate molecular and morphological information to clarify the stylasterid evolutionary scenario and represents the first step to infer the stylasterid ancestor morphology.

The genus Zygophylax Quelch, 1885 includes ca. 50 valid species of leptothecate hydroids that occur mainly in deep waters. Herein we describe Zygophylax kakaiba, sp. nov., collected in the Philippines at a depth of 580 m during the Siboga Expedition. Compared to its congeners, this species is distinguished by the abrupt curvature of the distal third of its hydrothecae towards the adcauline side.

Scleractinian reef corals have recently been acknowledged as the most numerous host group found in association with hydroids belonging to the Zanclea genus. However, knowledge of the molecular phylogenetic relationships among Zanclea species associated with scleractinians is just beginning. This study, using the nuclear 28S rDNA region and the fast-evolving mitochondrial 16S rRNA and COI genes, provides the most comprehensive phylogenetic reconstruction of the genus Zanclea with a particular focus on the genetic diversity among Zanclea specimens associated with 13 scleractinian genera. The monophyly of Zanclea associated with scleractinians was strongly supported in all nuclear and mitochondrial phylogenetic reconstructions. Furthermore, a combined mitochondrial 16S and COI phylogenetic tree revealed a multitude of hidden molecular lineages within this group (Clades I, II, III, V, VI, VII, and VIII), suggesting the existence of both host-generalist and genus-specific lineages of Zanclea associated with scleractinians. In addition to Z. gallii living in association with the genus Acropora, we discovered four well-supported lineages (Clades I, II, III, and VII), each one forming a strict association with a single scleractinian genus, including sequences of Zanclea associated with Montipora from two geographically separated areas (Maldives and Taiwan). Two host-generalist Zanclea lineages were also observed, and one of them was formed by Zanclea specimens symbiotic with seven scleractinian genera (Clade VIII). We also found that the COI gene allows the recognition of separated hidden lineages in agreement with the commonly recommended mitochondrial 16S as a DNA barcoding gene for Hydrozoa and shows reasonable potential for phylogenetic and evolutionary analyses in the genus Zanclea. Finally, as no DNA sequences are available for the majority of the nominal Zanclea species known, we note that they will be necessary to elucidate the diversity of the Zanclea-scleractinian association.

A number of stylasterid corals are known to act as host species and create refuges for a variety of mobile and sessile organisms, which enhances their habitat complexity. These include annelids, anthozoans, cirripeds, copepods, cyanobacteria, echinoderms, gastropods, hydroids and sponges. Here we report the first evidence of a diverse association between stylasterids and scalpellid pedunculate barnacles and describe a new stylasterid species, Errinalabrosa, from the Tristan da Cunha Archipelago. Overall, five stylasterid species are found to host eight scalpellid barnacles from several biogeographic regions in the southern hemisphere (Southern Ocean, temperate South America and the southern Indo-Pacific realms). There is an apparent lack of specificity in this kind of association and different grades of reaction to the symbiosis have been observed in the coral. These records suggest that the association between pedunculate barnacles and hard stylasterid corals has a wide distribution among different biogeographic realms and that it is relatively rare and confined largely to deep water.

Cyclic ADP-ribose (cADPR) is an intracellular calcium (Ca(2+)(i)) mobilizer involved in fundamental cell functions from protists to higher plants and mammals. Biochemical similarities between the drought-signaling cascade in plants and the temperature-sensing pathway in marine sponges suggest an ancient evolutionary origin of a signaling cascade involving the phytohormone abscisic acid (ABA), cADPR, and Ca(2+)(i). In Eudendrium racemosum (Hydrozoa, Cnidaria), exogenously added ABA stimulated ADP-ribosyl cyclase activity via a protein kinase A (PKA)-mediated phosphorylation and increased regeneration in the dark to levels observed under light conditions. Light stimulated endogenous ABA synthesis, which was conversely inhibited by the inhibitor of plant ABA synthesis Fluridone. The signal cascade of light-induced regeneration uncovered in E. racemosum: light --> increasing ABA --> PKA --> cyclase activation --> increasing [cADPR](i) --> increasing [Ca(2+)](i) --> regeneration is the first report of a complete signaling pathway in Eumetazoa involving a phytohormone.

The life cycle of Hydrozoans typically comprises two phases: the polyp, either solitary or colonial, with generally a benthic habitat, and the medusa which lives in the plankton. In its typical metagenetic cycle, the medusa is budded from the polyp, which is the product of sexual reproduction of medusae. However, several alternative reproduction patterns have also been described. In particular some species are able to perform a regressive transformation of the medusae that transform themselves into polyps bypassing sexual reproduction. In a species with alternative morphs switched by the environment, the more labile is the correlation between environmental factors acting on the genetic switch and the factors to which the resulting form is adapted, the more hazardous will be the development of either body form. However, we can explain the evolutionary advantage offered by reversion between morphs of these plastic species living in shallow water unpredictable environments: should produced medusae be released in the "wrong" environment, they would still have a chance of survival under another form.