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The minute bivalve Gregariella semigranata (Reeve, 1858) was first reported from the coralligenous algal reefs off of Marzamemi in southeastern Sicily. The species has a cryptic, nestling lifestyle within convolutions of calcareous algae and crevices, occurring also under the canopy of fleshy algae and inside the soft tissues of sponges. A peculiar cocoon of threads and agglutinated mud enveloping some Gregariella specimens was observed, partly filling the gaps between the shell and the walls of hosting crevices, with a possible function of protection and/or stabilization. The posterior half of the valves develops a hairy periostracum with a tuft of long branched barbules resembling the surrounding soft algae. The tuft is the only part protruding from the substratum, with a possible mimetic function against predators. The numerous specimens of G. semigranata from Marzamemi allowed us to better focus on the ecology and the life strategy of this bivalve and adds a further record from the Ionian coasts of Sicily to its known Mediterranean geographical distribution.

The coralligenous build-ups located on the Mediterranean shelf in front of Marzamemi (SE Sicily, Italy) represent useful natural examples to use in studying the relationship between skeletal organisms and non-skeletal components in marine bioconstructions. Coralligenous build-ups are formed in open marine systems, and their comparison with coeval bioconstructions (biostalactites) of confined environments, like submarine caves, allows depicting the complex interactions between metazoans and microbial communities in the formations of recent bioconstructions in different Mediterranean settings. In this study, two coralligenous build-ups were characterized in terms of organisms and sediments involved in their formation. The framework mainly consists of coralline algae and subordinate bryozoans and serpulids. Sponges affect the general morphology of the bioconstructions both interacting with skeletonized organisms and through bioerosion activity. The micrite or microcrystalline calcite is present in minor amounts compared to other components that form the build-ups and consists of two types: autochthonous (in situ) and allochthonous (detrital). Fine autochthonous micrite mineralized directly inside the framework cavities and shows aphanitic or peloidal fabric, produced by organomineralization processes of soft sponge tissues and microbial metabolic activity, respectively. The detrital micrite occurring inside cavities derives from external sources or erosion processes of the bioconstructions themselves. This component has been classified as organic or inorganic based on the organic matter contents deduced by UV epifluorescence. A great quantity of sponges live in cavities of the coralligenous build-ups and compete with carbonatogenic bacteria for the same cryptic spaces, limiting the production of microbialites. The sharing of a similar relationship between sponges and microbial communities by coralligenous concretion and biotic crusts of particular submarine caves sugge

Carbonate biomineralization in marine organisms normally occurs as three distinct types, known as: “controlled”, “induced” and “influenced”. Among invertebrates, reef-building polychaetes of the family Cirratulidae appear to provide the first example of “dual-phased” biomineralization as they simultaneously combine “controlled” and “induced” types in the formation processes of their aggregated tubes. Recently, Kočí et al. (2020) described the general morphology and internal framework of some bioconstructions of a Miocene cirratulid species and stressed the need of further comparative studies to better understand the nature of the calcareous matrix, tube ultrastructure and biomineralization processes. The main purpose of this work is to study the mineral structure of some Miocene (Diplochaetetes) and Recent (Dodecaceria) cirratulid bioconstructions from southern Peru through optical microscopy, epifluorescence, SEM-EDS analyses and morphometry. Results have also been statistically processed in order to highlight the possible relationships between size and chemical composition of the skeletal component with the morphology of the bioconstructions themselves, which in turn hints to environmental parameters. Three linear correlations, considering as variables morphological parameters (i.e., tube diameters) and the weight concentration of the main elements (Ca and Sr), were tested. Both fossils and recent specimens show similar correlations among composition and morphometric parameters, suggesting that the growth/evolution of these bioconstructions is presumably unaffected by environmental chemo-physical conditions. The primary ultrastructure of the tube walls points to controlled biomineralization, while the “intertube” areas of the bioconstruction, filled by a calcareous matrix frequently agglutinating extraneous sand grains, would be the product of an induced biomineralization. Agglutinated sand grains have various compositions and many of them are igneous, their ori

On the bottom of the circalittoral zone of the Mediteranean Sea, prevalently calcareous algae, and subordinately bryozoans, sponges and serpulids give rise to bioconstructions called Coralligenous (algal reef). It with different aspects, mostly columnar or dome-shaped, and different zoo-phitological compositions represent a true biodiversity hot spots on the sea bottom. Ostracod and foraminifer do not participate directly in the construction of the reef but they can contribute significantly to the increase in its degree of biodiversity. The present study wants to be the first attempt to analyze the composition and structure of the microfaunas associated with bioconstructions in an area located along the Ionian coast of SE Sicily offshore Marzamemi (SR, Italy). For this purpose, seven samples, picked up from the surface of the bioconstructions, were collected between 33 and 37 m depth using the sorbona sampling device. Living ostracod associations include 22 taxa: clearly dominant are the specimens belonging to the genus Xestoleberis, followed by the genera Neonesidea, Tenedocythere, Aurila, Loxoconcha, Urocythereis; poorly represented are the genera Carinocythereis, Paradoxostoma and Polycope. Foraminifers associations are almost exclusively represented by benthic phytal taxa and include over 3700 specimens belonging to 130 different taxa. The families quantitatively prevalent, both in terms of richness of species and abundance, are Elphidiidae, followed by Hauerinidae, Cibicididae, Ammoniidae, Homotrematidae, Planorbulinidae, Textulariidae, Cribrolinoididae, Asterigerinatidae, Rosalinidae, Spiroloculinidae and Globigerinidae that are subordinate, while little represented are Astrononionidae, Haplophragmoididae, Polymorphinidae, Ammodiscidae, Ellipsolagenidae, Spirillinidae etc.

Coralligenous (C) habitat consists of calcareous formations of biogenic origin characteristic of subtidal systems in the Mediterranean Sea. It develops only specific environmental conditions, and its growth is controlled by the delicate balance between bioconstruction and bioerosion processes. C outcrops typify specific areas of the Mediterranean continental shelves. Offshore Marzamemi village (southeastern Sicily, Ionian Sea) peculiar columnar-shaped C outcrops were documented in 2001. Nevertheless, an in depth study of their extension and distribution in the area is still missing. Indeed, this is one of the main goals of the project CRESCIBLUREEF - Grown in the blue: new technologies for knowledge and conservation of Mediterranean reefs . A new 17 km2 high-resolution morpho-bathymetric map was produced using a R2-Sonic2022 MBES system, ground-truthed by ROV surveys. The combination of bathymetric and backscattering data, together with the ROV videos, allowed us to identify five main habitats. From a geomorphological point of view, it was possible to divide the area into four main marine terraces. These terraced landforms are probably the result of eustatic sea-level variations coupled with tectonic processes. Of relevant importance is the correlation between C reefs distribution with this geomorphological layout. Indeed, C build-ups result to be more widely spread over the shallowest and deeper terraces at selected depth ranges, from 36 to 42 m and from 82 to 102 m of water depth, respectively. This study represents a starting point for the understanding of such a complex habitat, which is among the most important in the Mediterranean Sea and under protection by several legal instruments. Further investigations are needed to better understand the C settling in respect to this inherited continental shelf landscape. This is valid under both the biological and geomorhological point of view, as C habitat is a hotspot of biodiversity, and the outcrops affect present-da

Coralligenous Bioconstructions (CB) include calcareous build-ups of biogenic origin that typify selected regions of the Mediterranean continental shelves, where they formed since the Holocene transgression. They can be from few to tens of meters large, displaying variable lateral continuity and thickness. Offshore Marzamemi (south-eastern Sicily, Ionian Sea) the occurrence of peculiar columnar-shaped CB have been documented in 2002, but their actual extension and distribution across the shelf was not known until recent time. The project “CresciBluReef: New technologies for knowledge and conservation of Mediterranean reefs” produced a new17 km2 high-resolution bathymetric map using a R2Sonic2022 MBES, ground-truthed by ROV observations, that generated a good knowledge of the extension of CB in the region. The bioconstructions are preferentially distributed along selected depth ranges (from 30 to 40 m, and from 85 and 95 m of w.d.), with a good lateral continuity. The coupling of documented uplift rate (ca. 0.2 mm/yr since the Tyrrhenian time) and evidences reported in literature for Holocene relative sea-level curves, shows a good correlation between the distribution of CB and local and short stasis associated to the rapid Flandrian transgression. However, as revealed by the geomorphological map obtained by our study, a more in-depth investigation is needed to understand (1) the role of the inherited continental shelf landscape, shaped by previous low-stand periods, in creating favourable substrate for the settlement and growth of CB during the Holocene, and (2) the extent to which CB can in turn affect the evolution of present-day continental shelf landforms and landscapes.

Along the Mediterranean Sea shelf, algal reefs made of crustose coralline algae and Peyssonneliales are known as Coralligenous. It ranks among the most important ecosystems in the Mediterranean Sea because of its extent, complexity, and heterogeneity, supporting very high levels of biodiversity. Descriptive approaches for monitoring purposes are often aimed at assessing the surficial ephemeral canopy, which is sustained and controlled by the occurrence of the long-lasting rigid structure at the base. This practice led to the non-univocal definition of Coralligenous, sometimes indicated as “animal Coralligenous” because of the surficial dominance of these components. The quantitative assessment of the builders that actively build up the persistent structure through geological time is therefore a fundamental topic. We collected two discrete coralligenous samples in front of Marzamemi village (Sicily, Ionian Sea), the first from an area of a dense coralligenous cover (- 37 m) and the second one from an area with sparse build-ups (- 36 m). By using image analysis and computerized axial tomography, we distinguished and quantified the different components both on the surface and inside the framework. In both cases, our results confirm the primary role of crustose coralline algae as major builders of the Mediterranean Coralligenous, this aspect matching with the evidence from the Quaternary fossil record. We suggest that the role of encrusting calcareous red algae in the Coralligenous should be considered in conservation and management policies.

Crustose coralline algae (CCA) form Coralligenous build-ups, which are ranked among the most important ecosystems in the Mediterranean shelf. Their skeletal framework hosts a variety of epi- and infaunal communities, which compete for space, contributing to the reef growth, or weaken the structure throughout bio-erosive activities. Investigating the relationship between the algal framework and these hosted communities is of extreme importance for ecological and palaeoecological purposes and monitoring goals. In this frame, the Italian project “CRESCIBLUREEF - Grown in the blue: new technologies for the knowledge and conservation of the Mediterranean reefs”, is aimed at investigating coralligenous reefs present in the area off the Marzamemi village (South-East Sicily). Two build-ups have been collected: the first one at 37 m depth, from an area rich in coralligenous cover, and the second one at 36 m depth, from a submarine channel with sparsely distributed build-ups. We present here two new investigative techniques, so far seldom applied for the characterization of the Coralligenous. The first approach involved the quantification of the surficial cover, with the use of an image analysis software, both before and after the removal of their ephemeral canopy of unmineralized organisms.These models were then analysed using Object-Based Image Analysis (OBIA) algorithms that allowed the quantification of the surficial cover. Moreover, the analysis allowed the identification and categorisation of the organisms and materials on the external part of the build-ups, confirming the primary role of CCA as the major component of the samples. Afterwards, a Computed-Tomography (CT) scan was used - for the first time with Coralligenous - to reconstruct the inner structure of the build-ups and, together with radiocarbon dating, to infer the build-ups age and growth rate. CT analysis divided the framework into four main categories based on their density (Low, Medium, High and Ultra Hig

Coralligenous (C) is a type of Open Frame Reef, characterized by a variable association of calcareous red algae and macroinvertebrates. It is distributed across the Mediterranean shelf below the deepest seagrass meadows and down to the mesophotic zone, with different facies. The Italian project FISR “CRESCIBLUREEF” provided an extraordinary opportunity to explore the development of the Mediterranean C, from inception to present-day morphology and distribution off the SE coasts of Sicily. The spatial extension of C hybrid banks and discrete reliefs over the studied Sicilian shelf controls the hydrodynamics at the seafloor, the habitat biodiversity, and the related carbonate production at the shelf scale. The analyzed C samples, collected at about 36 m depth, had a columnar shape, were Holocene in age, and their development significantly modified the seafloor geomorphology. Our observations confirmed that most of the framework was built by calcareous red algae with an important contribution by bryozoans, with serpulids, molluscs, and rare corals as accompanying components of the sessile macroscopic fauna. The framework was highly porous, with a primary porosity derived from the growth, shape and structure of the skeletal components of both builders and dwellers, and an important secondary porosity derived from bioerosion and other early taphonomic processes involving both skeletonised and soft-bodied organisms, like sponges. During the entire process of framework growth and development, sponges played an important role as mineralization mediators of the autochthonous micrite fraction, which contributes significantly to the framework consolidation. Detrital micrite, rich in fine skeletal remains, is trapped in the primary and secondary cavities and represents an archive for the study of the organisms which are not directly involved in the framework building.

Coralligenous (C) include calcareous build-ups of biogenic origin, formed since the Holocene transgression. Peculiar columnar-shaped C outcrops were documented offshore Marzamemi village (SE Sicily, Ionian Sea), although the actual extension and distribution were not assessed. Project ‘CRESCIBLUREEF’ produced a new, 17 km2 high-resolution bathymetric map, leading to good knowledge about their extent in this area. C bioconstructions are largely distributed along two depth ranges 36–42 m and 86–102 m water depth. By coupling the documented uplift rate in this region and the Holocene sea-level curve, we were able to interpret the distribution of C outcrops over terraces. However, additional investigation is required to understand: (1) the role of the inherited continental shelf landscape, in creating a favorable substrate for the settlement and growth of C habitats during the Holocene, and (2) the extent to which C bioconstructions can impact the evolution of present-day continental shelf landforms and landscapes.

In the frame of the project FISR_04543 “CRESCIBLUREEF - Grown in the blue: new technologies for knowledge and conservation of Mediterranean reefs”, we present preliminary data on the ecological and depositional implications of micritic sediments in a coralligenous bioconstruction formed along the Mediterranean shelf in front of the Marzamemi village (Sicily, Italy). The framework of the buildup is mainly built by crustose coralline algae, which in turn create the substrate for a high-diversified epi- and infaunal community. Two types of microcrystalline calcite, tentatively interpreted as allochthonous and autochthonous micrite, strictly related to fine skeletal debris, have been detected. The allochthonous micrite derive from abiotic accumulation of fine sediments in the framework cavities. The autochthonous micrite is deposited in situ through organic-mediated processes. The occurrence of this component allows hypothesizing a possible contribution of non-skeletal carbonate in the strengthening of the primary framework due to its syndepositional cementation.

Although several bryozoans are considered habitat-former species, allowing colonisation by epibionts and promoting biodiversity, studies dealt so far with only some, usually constructional, species. In this context, the present study focuses on the epibiosis found on the erect mineralised but flexible species Margaretta cereoides, contributing with some macroalgae to the canopy formation on a coralligenous build-up collected at 36.7 m depth offshore Marzamemi (Ionian Sea, Mediterranean) in the frame of the project CRESCIBLUREEF. Focusing on bryozoans and serpulids we documented high diversity (species richness) on the investigated substrata (M. cereoides, Flabellia petiolata, Peyssonnelia rubra, Osmundaria volubilis and all other fleshy algae including Phyllophora crispa). Diversity, total number of colonies/specimens hosted, and number of colonies/specimens per cm2 are higher on M. cereoides than on algae, possibly in relation with the morphology, robustness and persistence of the surface offered by the bryozoan contrasting with the flexible and ephemeral nature of most algae, often provided with chemical defenses. Bryozoan and even more serpulid epibiont diversity on M. cereoides is also higher than those reported for studied species in the Mediterranean and for Flustra foliacea from North Europe.

The authors would like to apologise for any inconvenience caused. The authors regret that the Author affiliation details in the published article are incomplete. The affiliation details for Author Vittorio Quagliuolo should appear as Chirurgia Sarcomi, Melanomi, tumori rari, Humanitas Research and Clinical Hospital IRCCS. The full Author list and affiliation details are given here. Gabriella Ferrandina a,b, Cynthia Aristei c, Pietro Raimondo Biondetti d, Ferdinando Carlo Maria Cananzi e, Paolo Casali f,g, Francesca Ciccarone a, Nicoletta Colombo h, Alessandro Comandone i,j, Renzo Corvo' k,l, Pierandrea De Iaco m, Angelo Paolo Dei Tos n,o, Vittorio Donato p, Marco Fiore q, Franchi r, Angiolo Gadducci s, Alessandro Gronchi t, Stefano Guerriero u, Amato Infantev, Franco Odicino w, Tommaso Pirronti v,x, Vittorio Quagliuolo y, Roberta Sanfilippo z, Antonia Carla Testa a,b, Gian Franco Zannoni aa,ab, Giovanni Scambia a,b, Domenica Lorussoa,b a Fondazione Policlinico Universitario A. Gemelli IRCCS, Gynecologic Oncology Unit, Roma, Italy b Universita' Cattolica Del Sacro Cuore, Roma, Italy c Radiation Oncology Section, Perugia General Hospital, Perugia, Italy d Department of Radiology, Ca' Granda IRCSS Maggiore Policlinico Hospital Foundation Trust, Milan, Italy e Surgical Oncology Unit - Humanitas Clinical and Research Center, Rozzano, Italy f Department of Cancer Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy g Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy h Gynecologic Cancer Program, University of Milan-Bicocca and European Institute of Oncology, IRCCS, Milan, Italy i Division of Medical Oncology, Humanitas Gradenigo Hospital, Turin, Italy j ASL Città di Torino, Turin, Italy k Radiation Oncology Department, IRCCS Ospedale Policlinico San Martino, Genoa, Italy l Health Science Department (DISSAL), University of Genoa, Genoa, Italy m Unit of Oncologic Gynecology, Department of Obstetrics and Gynecology, University of

The authors would like to apologise for any inconvenience caused. The authors regret that the Author affiliation details in the published article are incomplete. The affiliation details for Author Vittorio Quagliuolo should appear as Chirurgia Sarcomi, Melanomi, tumori rari, Humanitas Research and Clinical Hospital IRCCS. The full Author list and affiliation details are given here. Gabriella Ferrandina a,b, Cynthia Aristei c, Pietro Raimondo Biondetti d, Ferdinando Carlo Maria Cananzi e, Paolo Casali f,g, Francesca Ciccarone a, Nicoletta Colombo h, Alessandro Comandone i,j, Renzo Corvo' k,l, Pierandrea De Iaco m, Angelo Paolo Dei Tos n,o, Vittorio Donato p, Marco Fiore q, Franchi r, Angiolo Gadducci s, Alessandro Gronchi t, Stefano Guerriero u, Amato Infantev, Franco Odicino w, Tommaso Pirronti v,x, Vittorio Quagliuolo y, Roberta Sanfilippo z, Antonia Carla Testa a,b, Gian Franco Zannoni aa,ab, Giovanni Scambia a,b, Domenica Lorussoa,b a Fondazione Policlinico Universitario A. Gemelli IRCCS, Gynecologic Oncology Unit, Roma, Italy b Universita' Cattolica Del Sacro Cuore, Roma, Italy c Radiation Oncology Section, Perugia General Hospital, Perugia, Italy d Department of Radiology, Ca' Granda IRCSS Maggiore Policlinico Hospital Foundation Trust, Milan, Italy e Surgical Oncology Unit - Humanitas Clinical and Research Center, Rozzano, Italy f Department of Cancer Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy g Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy h Gynecologic Cancer Program, University of Milan-Bicocca and European Institute of Oncology, IRCCS, Milan, Italy i Division of Medical Oncology, Humanitas Gradenigo Hospital, Turin, Italy j ASL Città di Torino, Turin, Italy k Radiation Oncology Department, IRCCS Ospedale Policlinico San Martino, Genoa, Italy l Health Science Department (DISSAL), University of Genoa, Genoa, Italy m Unit of Oncologic Gynecology, Department of Obstetrics and Gynecology, University o

Myxoid liposarcoma (MLPS) is a rare soft-tissue sarcoma characterised by the expression of FUS-DDIT3 chimera. Trabectedin has shown significant clinical anti-tumour activity against MLPS. To characterise the molecular mechanism of trabectedin sensitivity and of resistance against it, we integrated genomic and transcriptomic data from treated mice bearing ML017 or ML017/ET, two patient-derived MLPS xenograft models, sensitive to and resistant against trabectedin, respectively. Longitudinal RNA-Seq analysis of ML017 showed that trabectedin acts mainly as a transcriptional regulator: 15 days after the third dose trabectedin modulates the transcription of 4883 genes involved in processes that sustain adipocyte differentiation. No such differences were observed in ML017/ET. Genomic analysis showed that prolonged treatment causes losses in 4p15.2, 4p16.3 and 17q21.3 cytobands leading to acquired-resistance against the drug. The results dissect the complex mechanism of action of trabectedin and provide the basis for novel combinatorial approaches for the treatment of MLPS that could overcome drug-resistance.

Tube-dwelling cirratulids from the Miocene Chilcatay and Pisco Formations of southern Peru are described herein for the first time. These worms constitute tube aggregates cropping out in Burdigalian and Tortonian strata of the East Pisco Basin. These specimens are here referred to the extinct species Diplochaetetes mexicanus Wilson, 1986, which was so far known from the Oligocene and lower Miocene of the Pacific Mexico. The new finds represent the first described fossil record of cirratulids from South America. Different morphologies of the tube aggregates are described, as well as their internal framework and the tube wall features. The palaeoecological and palaeobiogeographical implications of these Miocene cirratulid reefs are then discussed.

Among the tube-dwelling polychaete worms in the family Cirratulidae, some species produce calcareous tubes preservable as fossils. Recent calcareous cirratulids are distributed in temperate and tropical environments, where they aggregate to form small reefs in shallow waters with normal salinity. Fossil records of cirratulid aggregates are however rare. Here we analyse the tube structure and taphonomic features of the cirratulid Diplochaetetes mexicanus (Wilson, 1986), reported from the Miocene of Peru, in the East Pisco Basin. There, the species forms dm-sized tube aggregates with pillow-, mushroom-, dome-like and tabular growth morphologies. Aggregates are formed by subparallel tubes adhering to each other. Tubes do not increase in diameter during growth and have a circular lumen with an average width of 1.3 mm. Transverse, concave upwards, double-layered septa occur inside some tubes. Optical and electron microscopy (SEM) analyses, coupled with epifluorescence observations, allow for detecting the tube biomineralization style. Tube wall is ca. 0.2 mm thick and is formed by a layer of very thin irregular micro-laminae. Sediment particles can be visible between tubes, cemented by biomicrites. Both the laminated wall and biomicrites in between show high fluorescence, reflecting their bio-mediated origin. The tubes exhibit different degrees of preservation. They vary from exquisitely preserved specimens, showing remain of the prismatic-like ultrastructure of the laminae and micrite-size crystals (finer than 4 microns) of the agglutinating biocement, to deeply diagenized specimens, showing rhomboedric dolomite crystals, growing on the original laminae and biomicrite. The present work aims at depicting the microstructure of the D. mexicanus and providing comparisons with the results obtained in previous studies.

Coralligenous (C) bioconstructions include calcareous build-ups of biogenic origin that typify selected regions of the Mediterranean Sea. These peculiar habitats thrive from shallow waters (15-20 m of water depth (w.d.) up to the limit of the mesophotic zone, and they formed since the Holocene transgression. They are from few to tens of meters large, displaying variable lateral continuity and thickness. Peculiar C outcrops are present offshore Marzamemi (southeastern Sicily, Ionian Sea). Their extension and distribution across the shelf were investigated within the project CRESCIBLUREEF - Grown in the blue: new technologies for knowledge and conservation of Mediterranean reefs. We produced a new 17 km2 high-resolution bathymetric map using a R2-Sonic 2022 system, ground-truthed by ROV video inspections. From a geomorphological point of view, the shelf is typified by four distinct marine terraces. Climate change and tectonic uplift are the dominant forcing mechanisms responsible for the formation of long and narrow terraced landforms in a variety of geomorphic settings; and marine terraces are largely used to reconstruct the Quaternary glacial and interglacial climates. The coupling of documented uplift rate in this region (ca. 0.2 mm/yr since the Tyrrhenian time) and the evidence reported in literature for late Quaternary relative sea-level curves shows a good correlation between the distribution of C outcrops and local, short stasis of sea level transgression periods, culminated with the rapid Flandrian transgression. C outcrops are mainly spread over the first and last terraces at two specific depth ranges: from 36 to 42 m of w.d., and from 86 to 102 m of w.d., respectively. Settlement and growth were mainly favored by a low sedimentation regime. Indeed, lowstand stages were likely characterized by erosional forces. This is particularly noticeable in the middle of our study area, where we have a paleo-incision typified by peculiar erosional features we were able t

Coralligenous Bioconstructions (CB) include calcareous build-ups of biogenic origin that typify selected regions of the Mediterranean continental shelves, where they formed since the Holocene transgression. They can be from few to tens of meters large, displaying variable lateral continuity and thickness. Offshore Marzamemi (south-eastern Sicily, Ionian Sea) the occurrence of peculiar columnar-shaped CB have been documented in 2002, but their actual extension and distribution across the shelf was not known until recent time. The project “CresciBluReef: New technologies for knowledge and conservation of Mediterranean reefs” produced a new 17 km2 high-resolution bathymetric map using a R2Sonic2022 MBES, ground-truthed by ROV observations, that generated a good knowledge of the extension of CB in the region. The bioconstructions are preferentially distributed along selected depth ranges (from 30 to 40 m, and from 85 and 95 m of w.d.), with a good lateral continuity. The coupling of documented uplift rate (ca. 0.2 mm/yr since the Tyrrhenian time) and evidences reported in literature for Holocene relative sea-level curves, shows a good correlation between the distribution of CB and local and short stasis associated to the rapid Flandrian transgression. However, as revealed by the geomorphological map obtained by our study, a more in-depth investigation is needed to understand (1) the role of the inherited continental shelf landscape, shaped by previous low-stand periods, in creating favourable substrate for the settlement and growth of CB during the Holocene, and (2) the extent to which CB can in turn affect the evolution of present-day continental shelf landforms and landscapes.