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– A-B, Corallistes masoni (Bowerbank, 1869), fragment of the holotype BMNH 77.5.21.7.; A, Inner surface view, B, Outer surface view. C, Corallistes bowerbanki (Johnson, 1863), holotype BMNH 69.11.60.1 PZS 1862, upper side view.
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Several lithistid sponges are described from Mediterranean caves occurring in the northwestern and Adriatic basins. In the Corallistidae, Neoschrommeniella bowerbanki and Neophrissospongia nolitangere are recorded for the first time from the Mediterranean, whereas Neophrissospongia radicle n. sp. and Neophrissospongia endoumensis n. sp. are describ...
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Citations
... Species found at two stations, both at the EB summit: one at 132 m and the other one at 152 m. Both stations corresponded to sponge grounds, with a great sponge diversity and abundance, including large tetractinellids like Discodermia polymorpha (Pisera & Vacelet, 2011) or Erylus spp., small axinellids and haplosclerids like Petrosia (Petrosia) ficiformis (Poiret, 1789) and Petrosia (Strongylophora) vansoesti (Boury-Esnault, Pansini & Uriz, 1994). ...
... The assignment of the northeast Atlantic and Mediterranean specimens to D. polydiscus was never satisfactorily argued, especially considering the distance between the type locality (Caribbean) and the Mediterranean Sea. Finally, Pisera & Vacelet (2011) described a new species, D. polymorpha, to include all the previous D. polydiscus Mediterranean records, from shallow caves to mesophotic depths in the Aegean Sea (210-360 m). The identity of the remaining northeast Atlantic records of D. polydiscus (Du Bocage (1869(1970); Cruz, 2002) are probably inaccurate but require proper revision of this material. ...
... The identity of the remaining northeast Atlantic records of D. polydiscus (Du Bocage (1869(1970); Cruz, 2002) are probably inaccurate but require proper revision of this material. Because D. polymorpha had extremely variable macroscopic and spicular characters, Pisera & Vacelet (2011) cannot exclude that it could represent a species complex. Our sequences match previous D. polymorpha sequences from its type locality, the 3PP cave, in La Ciotat, France (Chombard, Boury-Esnault & Tillier, 1998;Cárdenas et al., 2011). ...
The sponge fauna of the Western Mediterranean stands as one of the most studied in the world. Yet sampling new habitats and a poorly studied region like the Balearic Islands highlights once again our limited knowledge of this group of animals. This work focused on demosponges of the order Tetractinellida collected in several research surveys (2016–2021) on a variety of ecosystems of the Balearic Islands, including shallow caves, seamounts and trawl fishing grounds, in a broad depth range (0–725 m). Tetractinellid material from the North Atlantic and more than twenty type specimens were also examined and, for some, re-described in this work. All species were barcoded with the traditional molecular markers COI (Folmer fragment) and 28S (C1-C2 or C1-D2 fragment). A total of 36 species were identified, mostly belonging to the family Geodiidae (15 species), thereby bringing the number of tetractinellids recorded in the Balearic Islands from 15 to 39. Eight species from this study are new: Stelletta mortarium sp. nov., Penares cavernensis sp. nov., Penares isabellae sp. nov., Geodia bibilonae sp. nov., Geodia microsphaera sp. nov. and Geodia matrix sp. nov. from the Balearic Islands; Geodia phlegraeioides sp. nov. and Caminus xavierae sp. nov. from the North East Atlantic. Stelletta dichoclada and Erylus corsicus are reported for the first time since their description in Corsica in 1983. Pachastrella ovisternata is documented for the first time in the Mediterranean Sea. Finally, after comparisons of type material, we propose new synonymies: Geodia anceps as a junior synonym of Geodia geodina, Erylus cantabricus as a junior synonym of Erylus discophorus and Spongosorites maximus as a junior synonym of Characella pachastrelloides.
... Taxonomic studies of lithistid sponges living in submarine caves and dark tunnels have been mainly conducted in the Mediterranean Sea by several scientists (Pouliquen, 1969(Pouliquen, , 1972Pulitzer-Finali, 1970;Perez et al., 2004;Manconi et al., 2006;Manconi & Serusi, 2008;Pisera & Vacelet, 2011), and in the western Atlantic (Muricy & Minervino, 2000), Madagascar (Vacelet & Vasseur, 1965, 1971Vacelet et al., 1976) and Palau (Kelly, 2007). Recently, there were two reports about cave dwelling lithistid sponges: three species from anchialine caves of Yucatan Peninsula, Caribbean Sea (Gómez & Calderón-Gutiérrez, 2020), and four species from submarine caves of French Polynesia (Schuster et al., 2021b). ...
A new species of ‘lithistid’ (rock sponge) Sollasipelta subterranea sp. nov. is described from near-shore submarine caves of Okinawa and Shimoji Islands, the Ryukyu Islands, southwestern Japan. This new species is characterized by the smooth dentate ectosomal pseudophyllotriaenes, slender choanosomal oxea/style/subtylostyles and two types of amphiasters, one of which is in two size classes. Sollasipelta subterranea sp. nov. is morphologically closest to Sollasipelta sollasi (Lévi & Lévi, 1989), known from the Philippines deep sea, and our examination of the type specimen of S. sollasi revealed that the pseudophyllotriaenes and desmas are substantially different between the two species, and both species possess two types of amphiasters, one of which has two size classes. Sollasipelta cavernicola (Vacelet & Vasseur, 1965) and S. punctata (Lévi & Lévi, 1983) are transferred to the genus Daedalopelta Sollas, 1888, based on possession of one type of amphiastes as microscleres. Sollasipelta mixta (Vacelet, Vasseur and Lévi, 1976) is formally transferred to the genus Neopelta Schmidt, 1880, based on the morphological characters. A key to species of the genus Sollasipelta Van Soest & Hooper, 2020 is also provided. Sollasipelta subterranea sp. nov. represents the first ‘lithistid’ sponge from submarine caves of the Western Pacific and the first species of sponge inhabiting anchialine cave environments in the Indo-West Pacific. This is also a new record of the family Neopeltidae from Japanese waters.
... The Genus Neophrissospongia Pisera & Lévi, 2002 is composed of seven species, which are found in deep water (108-450 m) with some species occurring exclusively in caves (Lévi & Lévi, 1983;Manconi & Serusi, 2008;Pisera & Vacelet, 2011;Schuster et al. 2018;Van Soest & Stentoft, 1988). These species are characterized by shallow cup or ear-shaped forms, ectosomal dichotriaenes with tuberculated/spinose cladomes and streptasters/amphiasters among the microscleres (Pisera & Lévi 2002a). ...
... Remarks. The definition has been modified from that given by Pisera & Vacelet (2011) to include microstyles, microstrongyles and strongyles found in some specimens of Neophrissospongia microstylifera (Lévi & Lévi, 1983), Neophrissospongia radjae Pisera & Vacelet, 2011, Neophrissospongia nolitangere (Schmidt, 1870 Diagnosis. Neophrissospongia with skeleton composed of dicranoclone desmas with mushroom-shaped tubercles, dichotriaenes with tuberculated cladomes, acanthose microstrongyles and acanthose microstyles. ...
... Remarks. The definition has been modified from that given by Pisera & Vacelet (2011) to include microstyles, microstrongyles and strongyles found in some specimens of Neophrissospongia microstylifera (Lévi & Lévi, 1983), Neophrissospongia radjae Pisera & Vacelet, 2011, Neophrissospongia nolitangere (Schmidt, 1870 Diagnosis. Neophrissospongia with skeleton composed of dicranoclone desmas with mushroom-shaped tubercles, dichotriaenes with tuberculated cladomes, acanthose microstrongyles and acanthose microstyles. ...
In the present study, we describe two new species of Corallistidae from Brazil, comparing them to all valid species of the respective genera. Both are notable Porifera records, with the first specimen of Neophrissospongia Pisera and Lévi, 2002 registered for the Brazilian coast and the first specimen of Awhiowhio Kelly, 2007 registered for the Atlantic Ocean. The specimens were preserved in 80% ethanol and analyzed following classical procedure for Demospongiae, with dissociated spicule mounts, skeletal sections and Scanning Electron Microscopy. Neophrissospongia jorgeorum sp. nov. is differentiated from its congeners by the categories of spicules present, especially the lack of streptasters/amphiasters. Awhiowhio saci sp. nov. is characterized especially by the presence of spiraster-shaped microrhabds and microxeas.
... Although rock sponges (also known as lithistids or desma-bearing demosponges) are mostly known from the deep sea, they have been reported in shallow waters around the globe only from marine caves (Schuster et al., 2021 and references therein), especially in the northern and eastern Mediterranean Sea (Perez et al., 2004;Pisera & Vacelet, 2011;Pisera & Gerovasileiou, 2021). In most cases, particular caves harbour a single species that is usually unknown from other caves or habitat types. ...
3rd MEDITERRANEAN SYMPOSIUM ON THE CONSERVATION OF THE DARK HABITATS
... Although rock sponges (also known as lithistids or desma-bearing demosponges) are mostly known from the deep sea, they have been reported in shallow waters around the globe only from marine caves (Schuster et al., 2021 and references therein), especially in the northern and eastern Mediterranean Sea (Perez et al., 2004;Pisera & Vacelet, 2011;Pisera & Gerovasileiou, 2021). In most cases, particular caves harbour a single species that is usually unknown from other caves or habitat types. ...
Mediterranean echinoderms currently account for 154 species, many of which have been widely studied in coastal ecosystems. Investigations on deep-sea echinoderms, on the contrary, have been challenging in many ways, and very few targeted in situ studies have been carried out so far. Here we took advantage of an extensive ROV survey carried out in the Sicily Channel in 2021 to define the abundance, distribution, ecology and habitat references of two highly abundant yet poorly known deep echinoderms found in the explored area, namely the sea star Hymenodiscus coronata (Sars, 1871) and the holothurian Holothuria (Vaneyothuria) lentiginosa lentiginosa Marenzeller, 1892. About 2400 specimens of the brisingid sea star have been counted during the explorations between 150 and 950 m depth supporting the existence of dense bathyal aggregations on muddy planes. Several specimens of the dotted sea cucumber, an Atlantic species recently reported in the basin, were recorded on different substrates between 140 and 356 m, expanding the knowledge on the ecological preferences and bathymetric distribution of this species.
... Although rock sponges (also known as lithistids or desma-bearing demosponges) are mostly known from the deep sea, they have been reported in shallow waters around the globe only from marine caves (Schuster et al., 2021 and references therein), especially in the northern and eastern Mediterranean Sea (Perez et al., 2004;Pisera & Vacelet, 2011;Pisera & Gerovasileiou, 2021). In most cases, particular caves harbour a single species that is usually unknown from other caves or habitat types. ...
The anemone Amphianthus dohrnii (Koch, 1878) is a small opportunistic epibiont known to colonize a large variety of host species. The species is widely distributed in the eastern Atlantic Ocean and in the Mediterranean Sea, from mesophotic habitats to bathyal depths. Despite being very common, information on its ecology is currently scarce and scattered. The dataset used in this study was obtained during a ROV survey carried out in a wide area of the northern Sicily Channel. In total, 1369 specimens of A. dohrnii were counted. 82.9% of the specimens were observed colonizing dead branches of both living and dead corals, particularly bamboo corals (Isididae), Callogorgia verticillata, Paramuricea hirsuta, Leiopathes glaberrima and Madrepora oculata. Wrecks appear to be also a suitable substrate for A. dohrnii (14.9% of the records). 75.8% of the individuals were observed growing on the dead skeletons of bamboo corals, whose high availability may be related to a poor health status of the population.
... From the very first stages of marine cave research, it became evident that this peculiar habitat harbours several previously undescribed species (Sarà 1958, Vacelet & Lévi 1958, Vacelet 1959, Sarà & Siribelli 1960, Rützler & Sarà 1962. Until today, studies in Mediterranean marine and anchialine caves are continuously bringing to light new species from various taxonomic groups: Porifera (Vacelet & Boury-Esnault 1982, Pulitzer-Finali 1983, Pansini 1984, Bibiloni 1993, Corriero et al. 1996, 1997a, Bavestrello et al. 1997, Muricy et al. 1998, Pansini & Pesce 1998, Vacelet & Pérez 1998, Vacelet et al. 2000, 2007, Manconi et al. 2006, Pérez et al. 2011, Pisera & Vacelet 2011, Reveillaud et al. 2012, Melis et al. 2016, Lage et al. 2018, Priapulida (Todaro & Shirley 2003), Gastrotricha (Fregni et al. 1998), Copepoda , Carola & Razouls 1996, Jaume & Boxshall 1996, Jaume 1997, Jaume et al. 1999, Krsinic 2005, Decapoda (Pretus 1990, Fransen 1991, Mysida (Alcaraz et al. 1986, Wittmann 2004), Thermosbaenacea (Wagner & Chevaldonné 2020), Polychaeta (Zibrowius 1968, Fassari & Mòllica 1991, Gastropoda (Warén et al. 1997, Palazzi & Villari 2001, Crocetta et al. 2020), Bivalvia (La Perna 1998, Tardigrada (Villora-Moreno 1996), Bryozoa (Hayward 1974, Silén & Harmelin 1976, Harmelin et al. 2007, Rosso et al. 2020a), Brachiopoda (Logan & Zibrowius 1994), Chaetognatha (Casanova 1986) and Pisces (Kovačić 1999). ...
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.
... The Mediterranean submarine caves are all of karstic origin (limestones) and are a large biodiversity reservoir of sponge species that are otherwise only recorded from the deep-sea (Gerovasileiou & Voultsiadou 2012). In particular, the occurrence of a polyphyletic group of demosponges historically called lithistids (Pisera & Lévi 2002a;Schuster et al. 2015) seems to be highly abundant and thrive in these cave systems (Pérez et al. 2004;Manconi et al. 2006;Manconi & Serusi 2008;Pisera & Vacelet 2011;Pisera & Gerovasileiou 2018). Lithistids are characterized by an articulated choanosomal skeleton composed of siliceous desmas. ...
Lithistid demosponges are well known from limestone caves of karstic origin in the Mediterranean Sea. However, they have never been reported from submarine caves of volcanic origin in the South Pacific. Here, we describe and provide DNA barcodes for four new lithistid demosponges including one new genus. All species grew on basaltic rocks inside lava tubes on Nuku Hiva Island (Marquesas Islands) and Tahiti Iti peninsula on Tahiti Island (Society Islands) in French Polynesia. Three of the species have rhizoclone desmas as choanosomal skeletons and belong to the family Scleritodermidae (Microscleroderma miritatarata sp. nov. and Microscleroderma lava sp. nov.) and Siphonidiidae (Gastrophanella basaltica sp. nov.). The new genus Levispongia gen. nov. belongs to the family Corallistidae. The new species Levispongia meyeri gen. nov. sp. nov. has dicranoclone desmas, complex dichotrianes with strongly spinose upper surfaces of the cladome and microstyles as the only microscleres. Phylogenetic relationships of these new species are discussed and compared with other material from the Caribbean and Central to the West Pacific Ocean.
urn:lsid:zoobank.org:pub:844E385C-9A92-4F1B-B85C-9C1E319CD13F
... Sequences obtained for Discodermia ramifera were retrieved in a highly supported clade (PP 28S = 1; BS 28S = 93; PP COI = 1, BS COI = 98) with the Mediterranean species D. polymorpha Pisera and Vacelet (2011) in an equally monophyletic Discodermia spp. clade (PP 28S = 1, BS 28S = 93; PP COI = 1; BS COI = 98), sister to Theonella spp. ...
Lithistid sponges are globally distributed in temperate and sub-tropical areas, constituting an important component of deep-sea benthic communities where they form structurally complex and vulnerable marine ecosystems (VMEs). In this study, we assess the diversity and investigate the spatial and bathymetric distribution of the lithistid sponges of the Azores archipelago (North Atlantic) based on historical records and examination of samples accidentally collected during deep-sea longline fishing operations in the region. Eleven lithistid species are recognized to occur in the Azores, including Leiodermatium tuba, recently described from material collected in several Northeast Atlantic seamounts that is hereby reported for the first time to the archipelago. We provide molecular barcodes (mtDNA COI and rRNA 28S) for seven of these species, including Discodermia ramifera, Macandrewia azorica, and Exsuperantia archipelagus, for which the Azores constitutes the type locality. We further discuss the phylogenetic and biogeographic affinities of the Azorean lithistids in the context of the Porifera classification, and the wider Northeast Atlantic upper bathyal fauna. Our study also warrants the addition of some lithistid species to the list of VME indicators for the Northeast Atlantic in support of the sustainable management and conservation of these species and habitats, as well as the ecological functions they deliver.
... Ακόμθ, ςε πολλζσ περιπτϊςεισ οι ζρευνεσ ςτα καλάςςια ςπιλαια ζφεραν ςτο φωσ νζα είδθ για τθν επιςτιμθ από διαφορετικζσ ταξινομικζσ ομάδεσ οργανιςμϊν (π.χ. Harmelin et al. 2007, Pisera & Vacelet 2011, Zibrowius 1968), μερικά εκ των οποίων ςτο Αιγαίο (Lage et al. 2018, 2019, Rosso et al. 2020. Στα ςπιλαια όμωσ ςυναντϊνται και είδθ που δεν είναι προςαρμοςμζνα να επιβιϊνουν ςτο ςυγκεκριμζνο περιβάλλον και αποτελοφν «τυχαίουσ επιςκζπτεσ» που περιςταςιακά ειςζρχονται ςτο ςπιλαιο προσ αναηιτθςθ τροφισ ι για προςταςία. ...
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.
