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A submarine cave near Vrbnik (the island of Krk, Croatia) is 30 m long and has the shape of an irregular triangular prism, with its bottom covered by mud and boulders. Formed in Upper Cretaceous limestone under terrestrial conditions, probably during the Würm glaciation it was submerged during the Holocene rise in the sea-level. Preliminary bioceno...
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... An actual, comprehensive checklist of the Mediterranean mollusks was provided by Ramazzotti et al. (2016), but without specific references to the Adriatic Sea. In the last years the malacofauna of particular northern Adriatic Isles was intensively studied by sampling at numerous sites, with a focus on micromollusks (e.g., Arko-Pijevac et al. 2001;Romani et al. 2018;Romani et al. 2020;Raveggi et al. 2021;Kapeller 2023). ...
This issue 11 of ARIANTA has once again succeeded in presen�ting a colorful mixture of malacological topics. We would like
to thank the authors of the texts and illustrations as well as the
reviewers for their efforts and commitment. The fact that our
journal and its topics are not only frequented by mollusc ex�perts is also shown by the contribution of MoFA President Mi�chael Duda in the radio program “Aus dem Leben der Natur” in
the 17th calendar week 2024 on Ö1 about the “Mollusks of the
Bisamberg and the Alte Schanzen in Vienna”. A study published
in the last issue of our journal was the subject of five radio fea�tures. As a result, we registered an increased access to our web�site. In this way, we are also making an important contribution
to public relations work for mollusc research (and for molluscs).
... All dives were performed at about midday between 12:00 and 14:00 h in sunny clear weather conditions. The light was measured at the surface, immediately below the surface and at the cave entrance before entering the cave (Arko Pijevac et al., 2001). Because the goal was to capture the best representation of variability of the entire cave surface area, we chose a stratified systematic sampling approach to achieve equal representation of squares from different positions (cave bottom, cave walls, cave top) and equal representation at each position of squares along a range of distances from the cave entrance (Table 1). ...
... The following habitat characteristics were recorded: "Temperature" of sea water ( • C); "Light" ratio (%) of illumination (lux) measured at squares compared to illumination (lux) measured immediately below surface (Arko Pijevac et al., 2001); "Distance from the cave entrance" (m); "Depth" from the sea surface (m); "Position in cave" as cave bottom, cave wall, cave ceiling positions; "Surface inclination" as three estimated classes of surface inclination (degrees): horizontal (<45 • ), vertical (45 • -135 • ) and reverse (>135 • );"Bottom substrate" and "Biocover" as in Kovačić et al. (2012); "Bottom layers" as no layers of movable particles (e.g. pebbles or boulders) with hidden spaces in the interstitium or layers present;"Biological community" (the codes and terms from Bakran-Petricoli (2011) biocenosis of caves and ducts in complete darkness. ...
... The "cave within cave" fish can be considered "stygophiles" as defined in Gerovasileiou and Bianchi (2021), same as expected for the majority of marine cave biota (Gerovasileiou and Bianchi, 2021). In addition, although G. steinitzi occurs exclusively in the cave (Arko et al., 2001), one of these records was at the cave entrance (Kovačić et al., 2011). The present research has only scratched the surface of the ecological relationships of "cave within cave" fish species and marine cave fishes in general. ...
This study aims to describe for the first time the diversity and abundance of “cave within cave” fish species assemblage and to study the effects of habitat variables on these assemblage patterns. The term “cave within cave” is used to describe small, enclosed cavities and other enclosed spaces regularly present on the inner surface of large marine caves. The quantitative study was conducted from October to November 2019, in a large marine cave under Lučice Bay, on the south side of Brač Island in the eastern Adriatic Sea. In total 48 one-square-meter surface squares were sampled, extending 40m inside from the cave entrance, and down to a depth of 26m. A total of 18 fish species were found in the studied cave, of which 15 were recorded on the square frames. Nine species were found in intracave cavities, including five species which occurred exclusively in this highly cryptic habitat. The three strictly “cave within cave” fish species (Corcyrogobius liechtensteini, Didogobius splechtnai and Zebrus zebrus) prevailed by abundance and by frequency of occurrence over other twelve species recorded on the squares. The total fish abundance significantly increased with increased light intensity, with steeper surface and from the bottom to the top of the cave, while the total biomass and species richness significantly increased only with the increased light intensity. The assemblage structure of “cave within cave” fishes differed significantly with light intensity, among different surface inclinations and among different cave positions. The “cave within cave“ fish species differ in habitat preferences, some species inhabit the entrance of the cave with high light conditions and rich zoocover, and others inhabit further inside the cave with low light conditions.
... Sarà 1958, 1961a,b, 1962, Cattaneo & Pastorino 1974, Cantone et al. 1979, followed by contributions from Spanish scientists in the 1980s (Bibiloni & Gili 1982, Bibiloni et al. 1984, and by Croatian scientists since 2000 (e.g. Arko-Pijevac et al. 2001, Bakran-Petricioli et al. 2007, 2012, Petricioli & Bakran-Petricioli 2019. Studies of marine caves in the eastern Mediterranean were published more recently by Greek (Gerovasileiou 2014, Gerovasileiou et al. 2015aand references therein, Gerovasileiou & Voultsiadou 2016, Gerovasileiou et al. 2017b, Dimarchopoulou et al. 2018 and Turkish scientists (Öztürk 2019), with contributions also from Cyprus (Guido et al. 2017a, Jimenez et al. 2019 and Lebanon (Pérez et al. 2004, Ramos-Esplá et al. 2012, Castelló et al. 2020. ...
... In the dark part of caves with terminal air domes, the deep circalittoral bivalve Neopycnodonte cochlear was seen forming thick encrustations on rocky walls just below the water surface in marine caves of Salento and the Sorrentine Peninsula (Italy) and of Croatia (C.N. Bianchi, personal observations in 1979, Cattaneo-Vietti & Russo 1987, Arko-Pijevac et al. 2001, Novosel et al. 2002, Onorato et al. 2003. Some mollusc species were first described from marine caves, such as the gastropods Hyalogyra zibrowii, Skeneoides digeronimoi and Ocenebra vazzanai, and the bivalves Asperarca magdale nae, Neolepton discriminatum and Lucinoma spelaeum (Warén et al. 1997, La Perna 1998, Palazzi & Villari 2001, Crocetta et al. 2020). ...
Marine caves are biodiversity reservoirs and refuge habitats, harbouring rare species and living fossils. The Mediterranean Sea hosts more than 3000 caves, which are among the most studied in the world. This review aims to synthesize and update knowledge of Mediterranean marine caves. Their biota includes few obligate cave-dwelling organisms, but many cryptobiotic or crevicular (crevice-dwelling) and bathyphilic (preferring deep-water) species that secondarily colonize caves. A total of 2369 taxa have been reported from 404 caves in 15 countries, with several species new to science described in recent decades. Dramatic environmental gradients generate a zonation of the biota, with up to six faunal zones and two main biocoenoses. Biotic cover and biomass are strongly reduced inside caves, due to hydrological confinement and trophic depletion. The food web is based on suspension-feeders, but motile carnivores play a role in the importation of organic matter from outside. Lack of primary production, faunal affinities and microbial metabolism make marine caves readily accessible models of deep ocean ecosystems. Future research should focus on filling regional (e.g. south-eastern Mediterranean) and thematic (e.g. microbes, meiofauna, macroinfauna) gaps in fundamental knowledge, and on management measures. Marine caves have low ecological resilience and harbour many species of conservation interest, but are threatened by seawater warming, local human impacts and non-indigenous species.
... Steinitz's goby has been assigned to the "Least Concern" category in the IUCN Red List of Threatened Species, with an unknown population trend [40]. It has been reported along the north Mediterranean coastline from Spain to Turkey [6,15,23,30,33,[41][42][43][44][45] and has even been found in the Black Sea [14]. It is a cryptic goby that is known exclusively from the marine caves of the Mediterranean and the Black Sea. ...
... It is known to inhabit dimly lit biotopes such as crevices, caves, caverns, and underneath pebbles. More specifically, M. nigriceps has been reported in the Balearic Islands, Spain [10], France [52], Italy [11,12], Croatia [45,53], Montenegro [54], Greece [47], and Turkey [46,55]. Although it appears in shallow waters, there is a dearth of knowledge regarding M. nigriceps and its population trends due to its small body size and cryptic behavior. ...
Data on the distribution and ecology of cryptobenthic fish of marine caves in the Mediterranean Sea are extremely scarce but necessary for scientists and marine managers alike in order to understand these fish’s ecological role and assess their conservation status. Broadscale surveys by implementing underwater visual census and photographic sampling in marine caves of the northeastern Mediterranean Sea, within different expeditions during the last 5 years, brought to light new records of eight rarely reported cryptobenthic fish species. To a smaller extent, complementary citizen science data from diving professionals of Crete were used to fill distribution gaps. A total of 36 new records (66 individuals) from 18 marine caves and caverns of the Aegean and northeastern Levantine Seas were assembled, belonging to the gobies Corcyrogobius liechtensteini, Didogobius splechtnai, Gammogobius steinitzi, and Thorogobius ephippiatus, the blenny Microlipophrys nigriceps, the tripterygiid Tripterygion melanurum, the speleophilic bythitid Grammonus ater, and the gobiesocid Lepadogaster cf. lepadogaster. The above species have been rarely reported from the Eastern Mediterranean Sea, with D. splechtnai and G. steinitzi being recorded for the first and second time from Greek waters, respectively, while L. cf. lepadogaster constitutes the second record of a clingfish species in a marine cave of the Aegean Sea. Interesting behavioral and ecological habits were also noted for some species, based on in situ observations and photographic evidence. Our study contributes to filling gaps in the knowledge of cave fish diversity and demonstrates that cryptobenthic mobile species in understudied cryptic habitats are more common than previously thought in the Mediterranean Sea.
... Μεταξφ των ειδϊν που καταγράφθκαν βρζκθκαν και δφο είδθ που είναι γνωςτό πωσ προτιμοφν βακφτερα νερά. Το κοςμοπολίτικο δίκυρο Neopycnodonte cochlear που βρζκθκε ςτθ ηϊνθ ειςόδου και τθν θμιςκότεινθ ηϊνθ του ςπθλαίου Φωκοςπθλιά, το οποίο ζχει καταγραφεί λίγεσ φορζσ ςε ςπιλαια τθσ Ιταλίασ, τθσ Κροατίασ και του Β.Αιγαίου (Cattaneo-Vietti & Russo 1987, Arko-Pijevac et al. 2001, Novosel et al. 2002, Onorato et al. 2003, Gerovasileiou et al.2015a) και αρκετά άτομα του είδουσ Anthias anthias που βρζκθκαν ςε μικρά βάκθ ςτα ςπιλαια Άγιοσ Ραντελειμονασ και Οξϊνθςοσ (Εικόνα 17). ...
Sea caves constitute underwater cavities of various forms mostly filled with sea water. From the first studies on marine caves in the early 1950’s, scientists recorded a rich biodiversity in their interior unveiling new information about this unique marine ecosystem. Marine caves were soon considered as a habitat of European interest (type 8330 in the EU Habitats Directive) according to European and regional legislation. In the Mediterranean Sea they have been characterized as biodiversity reservoirs because they host various endemic, rare and protected species, as well as bathyal species, living fossils and unique bioconstructions.To date, more than 3,000 marine caves have been recorded along the Mediterranean coasts, more than 600 of which are found along the Greek coasts of the Aegean Sea. However, only few caves have been systematically studied for their biodiversity.
Through the present MSc thesis we aim to study both qualitatively and quantitatively the macrobenthic biodiversity of seven marine caves of the Protected Area of North Karpathos and Saria Islands (South-Eastern Aegean, Greece) through photographic frames analysis and visual census. It constitutes the first study in this area and one of the few for this marine habitat in the Eastern Mediterranean basin. The study was carried out at the Institute of Marine Biology Biotechnology and Aquaculture (IMBBC) of the Hellenic Center for Marine Research (HCMR) in Crete in the framework of the Master Studies Program “Environmental Biology” of the Biology Department, University of Crete.
The studied stations included seven marine caves, five located on the coasts of Saria Island and two on Karpathos Island. Among the caves of Saria Island, four constituted semi-submerged caves (Oxonisos, Giourious, Panteleimonas and Palatia) while the fifth (Alimounda) and the two caves from Karpathos Island (Fokospilia and Troulakas) were fully submerged. The studied sea caves were divided into three ecological zones: the entrance zone, where plenty of light intrudes, the intermediate semi-dark zone, where light is steeply reduced and the inner completely dark zone. A total of 140 photographic frames were collected along the different zones of the seven caves, ten from the entrance and semidark zone of every studied cave and five from the inner dark zone of two caves.
Sessile organisms were identified to the lowest possible taxonomical level and their surface coverage was calculated using the special software Photoquad for seabed image analysis. Motile taxa were recorded with visual census and photography during the dives.
In total, 78 sessile taxa were identified, 47 of which to the species level, 18 to genus and 3 to family level as well as 10 categorized to higher functional and morphological groups. Sessile taxa were represented by 33 Porifera, 17 Bryozoa, 12 Macroalgae, 5 Cnidaria, 3 Ascidiacea, 3 Brachiopoda, 2 Mollusca, 1 Foraminifera, 1 Polychaeta and 1 Cirripedia. In addition, 43 motile taxa were identified to species (39), genus (2) and family (2) level represented by 23 Pisces, 9 Crustacea, 6 Echinodermata, 2 Polychaeta, 2 Mollusca and 1 Mammalia. Eleven protected species are included in the abovementioned taxa, among which is the Mediterranean seal Monachus monachus, the dusky grouper Epinephelus marginatus, the spiny lobster Palinurus elephas and the Mediterranean slipper lobster Scylarides latus. The deep-water species Anthias anthias and Neopycnodonte cochlear, the commercial shrimp Plesionika narval and several rare species alongside with species considered as characteristic for the marine cave environment were also reported in the studied caves.
According to the results, different number of taxa was recorded at each of the ecological cave zones. At the entrance zone 72 taxa were recorded while 56 and 18 taxa were reported from the semidark and the dark zone respectively. Sponges presented the highest number of taxa at all ecological zones of the caves with Dedroxea lenis and Spirastrella cunctatrix presenting the highest surface coverage. Bryozoan taxa were reduced at the inner cave parts with Encrusting Bryozoa, Bryozoan turf and Ceberea boryi often being dominant.
In contrast, different taxa dominated in terms of surface coverage at different ecological zones of the studied caves. Rhodophyta had the most extensive coverage at the cave entrance varying from 25% to more than 45% of total entrance zone coverage. This is due to the sufficient for their survival intensity of light that penetrates the cave entrance. Their coverage was comparatively reduced at the less lightened inner zones where only Encrusting Rhodophyta, Mesophyllum sp., Peyssonnelia sp. and Palmophyllum crissum being present. Rhodophyta coverage was also reduced as the depth increased among the caves. For example, fully submerged caves such as Fokospilia and Troulakas seemed to present less coverage of photosynthetic taxa at their less lightened entrances. The arch of Alimounda, although submerged, receives higher quantity of light due to the large dimensions of its entrances.
As rhodophytes reduce their coverage at the inner semidark cave parts, space competitive sciaphilic sponges became dominant with coverage exceeding 50%. Bare substrate, polychaetes and brachiopods dominated at the cave darkest parts due to the reduced water renewal and the more oligotrophic conditions. These conditions enable more sufficient filter feeders as well as small-sized and encrusting sponges (like Spirastrella cuncatrix) to replace larger and erect sponges.
Multivariate community analysis demonstrated that geomorphological and topographical factors of the studied caves are significantly associated with the observed biotic patterns. These factors were: Ecological zone, Cave, Entrance surface area, Entrance depth, Orientation and submersion level (submerged or semi-submerged). Different factors appeared to be statistically correlated with the resemblance patterns. According to one-way ANOSIM analysis pairwise tests, all caves were statistically significantly differentiated when quadrats from all cave zones were pooled together, but also when quadrats from the entrance and the semidark zone were examined separately. Regarding the factor of ecological zone, pairwise tests showed no significant differentiation between the semidark and the dark zone, possibly due to the limited number of quadrats from the darkest cave parts. Heterogeneity between the entrance and the inner sciaphilic ecological zones was in agreement with previous studies on comparative qualitative analysis of macrobenthic biocommunities of Mediterranean marine caves. Furthermore, community structure of the entrance zone was not differentiated between caves deeper than 11 meters and entrance surface area bigger than 110m2. Semi-submerged caves different significantly from fully submerged caves, probably due to the different light levels and hydrodynamic regime.
Several pressures and threats were recorded in all studied caves as well, including accumulation of plastic litter and occasional necrosis of sessile taxa. Non-indigenous species were reported in all the studied caves constituting of species that had previously been recorded at different ecosystems of the same area. Such species were: the gastropod Cerithium scabridum, the long-spined sea urchin Diadema setosum and seven alien fishes (Parupeneus forsskali, Pempheris rhomboidea, Pterois miles, Sargocentron rubrum, Siganus luridus, Siganus rivulatus and Torquigener flavimaculosus).
The abovementioned pressures could indicate signs of possible ecological degradation. Moreover, in order to further understand the community structure of the studied caves, additional samplings are needed to identify the species grouped at bigger functional and morphological groups. Emphasis should also be given to less known groups as well as sponges of the family Plakinidae, encrusting bryozoans and polychaetes. Future studies on the same marine caves should also focus on soft substrate macrofauna, as well as cryptobenthic species of fish and crustaceans.
Building upon the findings of this work, several management and conservation actions were proposed to the Management Agency of the Protected Area, aiming at highlighting and protecting marine caves and their biota. Among the proposed actions are: a monitoring plan for the assessment of both biotic (qualitative and quantitative biodiversity assessment) and abiotic (e.g. water temperature and pH) factors every two years in order to detect potential effects of climate change. Assessment of macro- and microplastics quantity and alien species could provide valuable information about their longterm effects on both marine caves and their surrounding ecosystems. Actions for raising public awareness and training seminars for divers and local citizens as well as creation of a protected zone focusing for selected caves could ensure the future protection of this unique marine ecosystem.
... Caves themselves cannot be of Mesozoic or even Paleogene in age. Most of the karstic caves in the Mediterranean region originated subaerially, most probably during glaciations (especially last glaciation, i.e., during the period between 115,000 to 11,700 years ago) and were submerged after (Arko-Pijevac et al., 2001). Thus, cave invertebrates, including the studied here lithistid demosponges must have colonized the surveyed caves rather recently, after the last glaciation. ...
Desmas-bearing demosponges known as lithistids have heavily silicified skeleton and occur typically in bathyal environments of warm and tropical areas but may be found in certain shallow marine caves. Here we report, for the first time two lithistid species, i.e., Neophrissospongia endoumensis, and N. cf. nana, that were earlier known from Western Mediterranean marine caves, from four marine caves in the north-eastern Mediterranean, and their congener Neophrissospongia nolitangere from deep waters (ca. 300 m) of the Aegean Sea. All marine caves, and sections within these caves, where lithistids occur, have freshwater springs. We interpret this surprising association between lithistids and freshwater input by elevated concentration of silica in water in cave sections where such springs occur, being 8–11 times higher in comparison with shallow water outside caves, and comparable to that of deep waters, that promoted lithistids’ development. One of the studied caves harbored an abundant population of N. endoumensis which formed large masses. The age estimation of these lithistids, based on known growth rate of related deep-water sponges, suggest that they could be approximately 769–909 years old in the case of the largest specimen observed, about 100 cm large. These sponges could have colonized the caves from adjacent deep-water areas not earlier than 7,000–3,000 years ago, after the last glaciation, because earlier they were emerged. High variability of spicules, especially microscleres, and underdevelopment of megascleres may be related to silicic acid concentration.
... hr/spilja_biserujka_eng.html]. There is also a marine cave at Vrbnik on the island's east coast which has received recent academic attention [Arko-Pijevac et al., 2001]. 8 At all events, it is clear that striking geological features are a signifi cant aspect of Krk's appearance, though that in itself does not distinguish it decisively from other Croatian islands nor from the adjacent Dalmatian coast. ...
Krk is one of the two largest islands in the Adriatic archipelago of Croatia, along with Cres. Its name has been discussed most recently by Dubravka Ivšić Majić (Voprosy Onomastiki 16.1, 2019) in the context of an analysis of the survival of the pre-Slavic names of islands presently in Croatia that are recorded in medieval sources, which is based in part on her doctoral dissertation. However, Krk has apparently never been discussed in the wider perspective that is attempted here. The purposes of this article are (1) to examine a moderately large range of similar names in or adjacent to the Mediterranean (understood broadly to include the Ægean, Adriatic and Tyrrhenian Seas), and (2) to try to form a view about the possible origin and significance of the name and its etymon, along with their possible relation to certain other names and lexical words in languages of the Mediterranean, notably Ancient Greek, and Insular Celtic. Particular attention is paid to the geology, geomorphology and cultural significances of the places bearing names of this type. It is tentatively concluded that the names originally referred to striking geological features invested with cultural significance because of some exceptional additional characteristic, such as the mysterious appearance or disappearance of pure water. Certainty is not possible about the language of original formulation, but the range of variation in the nametypes and their apparent dialectology are considered. Greek is the medium of transmission for the majority of the names analysed. A brief footnote glance is taken at superficially comparable names and lexical items even further from the epicentre of the phenomena considered here.
... Main habitat types in the submerged karst, characteristic of the Eastern (mainly Croatian) part of the Adriatic Sea, are anchihaline caves, sea caves, cold sea caves, pits with bathyal elements, vruljas (submarine springs), karst estuaries, submerged river canyons, submerged tuffa barriers, marine lakes, and bare karst in the sea (Bakran-Petricioli & Petricioli, 2008). In the Croatian part of the Adriatic, the marine caves and their environment have been thoroughly studied in terms of biology and morphology as also as a valuable archive of the evidence of sea level changes (Garašić, 1991;-Pijevac, Benac, Kovačić & Kirinčić, 2001;Bakran-Petricioli et al., 2007;Surić, Lončarić & Lončar, 2010;Radolović, Bakran-Petricioli, Petricioli, Surić & Perica, 2015). Unfortunately, only few such studies exist for the Montenegrin and Albanian coasts (Belmonte, Constantini, Moscatello, Denitto & Shkurtaj, 2006;Mačić, 2014;Mačić, Panou, Bundone & Varda, 2015;RAC SPA 2016). ...
Marine caves are classified as a biodiversity hotspot and priority habitat by the EU Habitats Directive. Despite of this fact, no information was available on these habitats and their associated species for the South Dinarides karst along the Adriatic coast of Montenegro. During 2013-2016, we surveyed the entire coastline of Montenegro (288km) in order to register and map the semi-submersed marine caves of the country. A total of 70 caves were registered of which 2 caves were 17m long and 22 caves were 25 m long or longer. The majority of the investigated caves were anchihaline (with fresh water overlying the sea water) while only few caves were euhaline (completely under marine conditions). Some caves were found to host considerable biodiversity and the presence of 6 protected and endangered species was registered inside the caves. During the surveys caves with morphological features suitable as potential habitat for the endangered Mediterranean monk seal (Monachus monachus) were also highlighted. Given the abundance and diversity of organisms registered in these marine caves further surveys are needed in order to document in detail the biodiversity and the habitat characteristics, as well as to ensure the protection of these endangered habitats.
... This is rather a consequence of higher hydrodynamics and instable environmental conditions than oligotrophy, which is rare in this type of caves. Sponge species composition in caves of Bulgaria as well as Crimea is different from those studied in the Mediterranean (Pouliquen, 1972;Balduzzi et al., 1989;Harmelin & Vacelet, 1997;Arko-Pijevac et al., 2001;Gerovasileiou & Voultsiadou, 2012;Manconi et al., 2013), probably due to the geographic isolation of the Black Sea and the differences in the hydro-chemical parameters of the milieu. ...
Marine caves possess unique biocoenotic and ecological characteristics. Sessile benthic species such as sponges associated with cave habitats typically show a marked zonation from the cave entrance towards the end of the cave. We describe three semi-submerged karstic caves of 50 to 83 m length and 936 to 2,291 m3 volume from the poorly explored cavernicolous fauna of North-East Bulgaria. We surveyed sponge diversity and spatial variability. Eight demosponge species were identified based on morphological and molecular data, of which six are known from the adjacent open sea waters of the Black Sea. Two species, Protosuberites denhartogi van Soest & de Kluijver, 2003 and Halichondria bowerbanki Burton, 1930, are reported from the Black Sea for the first time. The spatial sponge distribution inside the caves is in general similar, but shows some differences in species composition and distribution depending on cave relief and hydrodynamics. The species composition of sponges of Bulgarian caves is found to be different from Crimean caves. An updated checklist of the Black Sea sponges is provided.
... The vast majority of species found in the studied caves have already been reported from cave habitats in the Western Mediterranean including the Ibero-Provençal basin (e.g. Harmelin 1969Harmelin , 2003Monteiro-Marques 1981;Zabala and Gili 1985;Martí et al. 2004) and the Tyrrhenian Sea (Balduzzi et al. 1989;Di Geronimo et al. 1993, 1997, 2000Taddei Ruggiero et al. 1996), and/or in the Adriatic (Arko-Pijevac et al. 2001) and the western Ionian Sea (Rosso et al. 2013a;Sanfilippo et al. 2015). Several of these species are typical elements of cave habitats (see Rosso et al. 2013b). ...
Although bryozoans are one of the dominant sessile phyla in Mediterranean marine caves, little information is available on the bryozoan diversity of this habitat in the eastern basin. In this study, bryozoan assemblages of two Aegean marine caves located at different depths and characterised by different morphology were studied. The examination of 30 quadrats (20 × 20 cm) scraped from the vertical walls and cave ceilings, at increasing distances from the entrances, yielded 74 taxa (67 living and 47 dead), half of which were shared by both caves. Cheilostomes largely prevailed (59 taxa) over cyclostomes and ctenostomes (14 and 1 species, respectively). Nodular to fungiform bioconstructions were formed by species with multilayered colonies in both caves. Differences in the taxonomic structure of bryozoan assemblages between the two caves as well as on the spatial variability of diversity, abundance and growth morphologies within each cave seem to be linked to the different cave morphology and associated environmental conditions. Moreover, a considerable number of taxa were reported for the first time from the Eastern Mediterranean and the marine cave habitat, supporting the idea that knowledge of their bryozoan diversity is far from being considered complete.
