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Biological invasions are one of the major threats to the ecosystem structure and functioning. After the initial introduction, frequently mediated by human activities, alien species can overcome different biogeographical and ecological barriers and determine severe impacts on native biodiversity and socio-economic activities. The Italian peninsula is located at the intersection of large trade routes within the Mediterranean Sea. Such position, along with the intense commercial activity and the high population density of the Italian coast, are considered important drivers of alien species in Italian marine and transitional ecosystems. The Italian peninsula, however, is also one of the regions with the highest native species richness within the Mediterranean Sea and, therefore, it is crucial to account for both alien and native species diversity when estimating the impact of biological invasion. Yet, such comprehensive information is frequently scattered across several biodiversity information systems and databases. Here, two datasets with alien and native species records in Italian marine and transitional waters are described. These datasets, created for the LifeWatch Italy case study on alien species, are the result of a large-scale collaboration involving experts working across the whole range of taxonomic diversity. The marine dataset includes a total of 12,219 records belonging to 3,772 species gathered from 91 investigated sites and seven EUNIS habitats. The dataset on transitional waters biodiversity includes 3,838 records belonging to 2,019 species found in 23 locations and four EUNIS habitats. Alien species were recorded in both marine and transitional waters, accounting respectively for 140 and 171 biological records belonging to 59 and 97 species. These occurrence data can be used for further research studies or management purposes, including the evaluation of the invasion risk and the formulation of alien species control and management plans. Furthermore, these compiled datasets can be used as input data for the Biotope vulnerability case study of LifeWatch ERIC, which offers a number of ICT services for the calculation of the incidence and of the impact of alien species on European biotopes.

The European wildcat is a small carnivore widespread across Europe and hybridization with the domestic cat is one of the major threats to wildcats. We estimate the population density of wild-living cats (both wildcats and putative hybrids based on pelage) in the Gargano National Park (Southern Italy). We sampled 20 stations for 540 camera days. We obtained 23 images from 17 detections at 10 cameras, and we identified 10 individuals (6 wildcats and 4 putative hybrids). Population density was estimated at 0.34 ± 0.15 SE wild-living cats/km2. The proportion of putative hybrids indicates an alarming hybridization for this population.

The analysis of 879 ROV dives carried out along the Italian coasts on hard substrata at mesophotic and upper bathyal depths (40-775 m) allowed us to evaluate the current basin-scale presence, relative abundance, bathymetric limits, and habitat preferences of one of the most charismatic Mediterranean habitat-former anthozoan species, Corallium rubrum (Linnaeus, 1758). The species is widespread, and its occurrence ranged from 13% of the explored sites in Ionian Calabria to a hotspot of approximately 80% in Sardinia. Population relative densities were generally low (< 10 colonies m-2), except along the Sardinian coasts and in some areas along the Apulian coast. Almost no red coral colonies were observed between 60 m and 590 m in the nine explored offshore seamounts in the Ligurian and Tyrrhenian Seas. A distinctive coastal distribution discontinuity was found in the Ionian Sea. The optimum bathymetric distribution was between 75 m and 125 m, and no colonies were found below 247 m. Red coral colonies showed a preference for biogenic habitats dominated by crustose coralline algae (CCA) and vertical substrata. The species was absent on iron wrecks. Corallium rubrum disappeared from 14% of the historical fishing banks, while it was confirmed in 86% of them, some of which have been deeply harvested in the past. In particular, the still flourishing Sardinian populations could be supported by the high reproductive potential and favourable hydrodynamic conditions in the area.

Lack of detailed knowledge on ecological niche, life cycles, spatial distribution, reproductive biology and space use strongly affects the selection of useful tools and measures in the conservation of threatened marine species. Especially for sedentary and slow species, behaviour and movement capacities are supposed to be the most important functional traits. Indeed, behavioural variability concerning available space and the close presence of individuals is considered a crucial trait for the population dynamics assessments, especially when disturbances of various causes are present in the environment. The present study aimed to investigate the site fidelity and degree of movement of Hippocampus guttulatus, an emblematic and threatened Mediterranean seahorse species. With this aim, a number of seahorses were tagged and monitored throughout two years within a limited area of the lagoon of Mar Piccolo of Taranto (Southern Italy). The studied individuals were initially morphometrically measured for size, sex and life-cycle stage and subsequently monitored through repeated four-month surveys each year. Obtained results indicated high site fidelity regardless of habitat type. Movement pattern was in line with the data on congeneric species, although values were slightly higher. The analyses showed differences in movement degree among different sexes and life-cycle stages and indicated greater mobility of adult females compared to males and juveniles. The investigated parameters showed a great variability suggesting that even small-scale environmental factors can influence the species mobility. Finally, a change in the population structure has been observed, with the loss of large individuals in 2016 and reduced recruitment in 2017. These findings indicated the possible presence of stressors that could lead to the alteration of the seahorse population at Mar Piccolo of Taranto.

Among large-sized mammals, the wild boar Sus scrofa is the main agricultural pest in Mediterranean countries. Despite being a widely studied species, its physiological adaptability requires a high number of research works assessing its ecology in different habitat types. Furthermore, little is known about ecology of the wild boar at the southernmost limits of its distribution range. We studied home range size, habitat selection and activity rhythms of female wild boar in a protected area of Southern Italy, at the limits of its distribution range. Population density was also assessed through drive counts. We monitored GPS collar-tagged, adult wild boar for at least 6 months. Female family groups selected deciduous woodland throughout the year, whereas scrubland and cultivations were selected only during the summer. Locations of wild boar were much closer to the forest edge than expected by chance alone. Throughout the year, female wild boar were mostly active between dusk and dawn with no significant inter-seasonal differences in the activity time; diurnal activity occurred principally in winter and spring. Wild boar were more active in the darkest nights, while their activity decreased in the full moon nights, possibly to limit encounters with the main predator, the grey wolf Canis lupus.

Seahorses are considered a flagship species for conservation efforts and due to their conservation status, improving knowledge on their dietary composition while applying a non-invasive approach, could be useful. Using Hippocampus guttulatus as a case study, the present study represents pioneering research into investigating the diet of seahorses by NGS-based DNA metabarcoding of fecal samples. The study developed and tested the protocol for fecal DNA metabarcoding during the feeding trials where captive seahorses were fed on a diet of known composition, the process was subsequently applied on fecal samples collected from wild individuals. The analysis of samples collected during the feeding trials indicated the reliability of the applied molecular approach by allowing the characterization of the effectively ingested prey. In the field study, among detected prey species, results revealed that the majority of the seahorse samples contained taxa such as Amphipoda, Decapoda, Isopoda, and Calanoida, while less common prey taxa were Gastropoda and Polyplacophora. As only a small amount of starting fecal material is needed and the sampling procedure is neither invasive nor lethal. The present study indicates DNA metabarcoding as useful for investigating seahorse diet and could help define management and conservation actions.

The seahorse Hippocampus guttulatus reaches its highest abundance in confined environments, where it has unique biological and ecological traits that suggest significant genetic differentiation among populations. In the present study, we aimed to reveal the genetic structure of this species by analysing eight microsatellite loci and a mitochondrial DNA region (cytochrome b) of eight populations from the Central–Western Mediterranean Sea, including lagoon sites. Levels of genetic diversity, as measured by the total number of alleles, number of private alleles, allelic richness and heterozygosity, ranged from low to moderate. The overall value of inbreeding was high, indicating a deficiency in heterozygotes. The haplotype network had a star-like construction, with the most common haplotype present in all populations. Data from the two molecular markers congruently displayed a similar pattern and revealed low genetic differentiation, notwithstanding predictions based on species traits. The observed genetic structure is probably the result of both historical population demographic events and current gene flow. The investigated lagoons, however, revealed a unique genetic profile, which is especially highlighted by the Taranto population. At this site, the results also showed altered values of observed/expected heterozygosity and allelic richness, a characteristic of marginal populations. Our study suggests that lagoon populations should be managed as distinct genetic units.

Skin filaments are present on the heads of several Hippocampus species. Their clipping is a useful, non-lethal technique for marking individuals and sampling tissue. Little is known about the consequences of clipping on behaviour and details of regeneration. We present the results of a study on the effects of filament clipping on activity patterns and the regeneration of this structure at the macroscopic and microscopic level in Hippocampus guttulatus Cuvier, 1801 from the Gulf of Taranto (Apulia, Ionian Sea). Twelve individuals of both sexes underwent filament clipping, and their behaviour sequences (expressed as percent of total time spent swimming, resting, food searching, and swinging) were monitored for 10 wk in water tanks. In the first week, individuals spent significantly more time food searching and swimming compared to controls, whereas in the following weeks, no differences between groups were observed. Regeneration was observed in 12 other individuals reclipped after 3, 5, and 7 wk. Sections of paraffin-embedded filaments were stained with Mallory’s trichrome, alcian blue pH 2.5, periodic acid-Schiff (PAS), and PAS with diastase. Epidermal cells and basal membranes were the first to recover fully. Basal epidermal cells were filled with glycogen. In the dermis, the arrangement of bundles of fibres surrounded by melanocytes took longer to reconstitute. After 10 wk, the filaments grew to about 36.7% of their original length, whereas at the microscopic level, the tissues recovered fully. It is concluded that filament clipping does not significantly affect the general behavioural patterns of H. guttulatus, and regeneration at the microscopic level is fully accomplished.

Sponge assemblages associated with coralligenous outcrops were studied with the aim of describing and comparing their composition, morphological features and distribution at different depths (shallow vs. deep) along the Apulian coasts. In addition, image analysis enabled the description of the main features of coralligenous outcrops and the detection of structuring species. The paper provides a significant contribution in terms of supplying new taxa of sponges associated to coralligenous assemblages and emphasising the importance of invertebrates in realising calcareous constructions. Most of the new finding came from deep sites, thus underlining the need to improve taxonomic studies on coralligenous communities at greater depths. A total of 153 taxa of sponges were recorded: 4 Calcarea, 6 Homoscleromorpha and 143 Demospongiae. Two species, Clathria (Microciona) macrochela and Thoosa armata, are new records for the Italian sponge fauna, with C. (M.) macrochela representing a new record for the whole Mediterranean. New findings for the Ionian and Adriatic Seas totalled 25 and 8 species, respectively. Thirty-nine species are endemic for the Mediterranean. Data analyses clustered sites into two groups, separated according to the depth. Deep sites, characterised by animal dominance, exhibit a heterogeneous substrate texture richer in cavities than the shallow and homogeneous algal ones. Differences in sponge species composition also correspond to differences in the distribution of sponge growth forms, with the insinuating cryptic species more abundant in deeper communities. Ten of 15 sponge species included in national and international wildlife protection laws and policy have been detected in the present study.

Here we describe two new species of deep-sea sponges collected during the exploration of Cold-Water Coral (CWC) banks discovered in the Nora and Coda Cavallo canyons (north-eastern and south coast of Sardinia respectively). Poecillastra tavianii n. sp. differs from the other congeneric species mainly for the dicho- and mesodichotriaenes, never observed in the genus, and the abundance and variety of spirasters. Hymedesmia (Hymedesmia) quadridentata n. sp. is characterized by the presence of two types of chelae. In particular, the unguiferate chelae (round shaft and four teeth at both extremities) represent a peculiar character of the species. Our contribution increases the number of sponge fauna associated to the best known Central Mediterranean CWC habitats to 98 improving the still scant knowledge on the biodiversity of the Mediterranean CWC habitats.

By using the LifeWatch database – a European e-science infrastructure on native and alien plant occurrence collected from a wide set of Italian terrestrial sites – we estimated the occurrence of alien species in a cross-habitat framework in relation to propagule pressure (P), abiotic (A) and biotic (B) conditions. The research represents an example of macro-ecological assessment of invasion risk at national scale claimed by the recent European regulation (EU 1143/2014) on invasive alien species. Based on a large vegetation dataset, we estimated alien and native species richness across a set of 19 Italian terrestrial sites. By using a Generalized Linear Mixed Model, we investigated the relationship between the proportion of alien occurrence across sites and habitat types (EUNIS) at family level with PAB putative drivers derived from LifeWatch and other open access geographic databases. Our results support the full model as the best-fitting option, highlighting that plant invasion in the Italian terrestrial ecosystems is a function of the combination of PAB conditions. In the first step of the invasion process, the accessibility time from towns plays a major role. By contrast, the abiotic filter imposed by environmental condition (high temperatures and low precipitations) as well the competition with the native community (high species richness) may pose a limit to the settlement and spread of alien species. Because of the high availability of similar data on PAB conditions worldwide, this study represents an effective and easy tool to design appropriate biodiversity conservation policies focused on the prevention of alien spread.

Population abundance, distribution and habitat preference of the Mediterra-nean sympatric seahorses Hippocampus guttulatus and Hippocampus hippocam-pus were investigated in a semi-enclosed sea system (Apulian coast, IonianSea). A total of 242 individuals of seahorses were sighted in the 11 transectssurveyed in summer 2011. Hippocampus guttulatus (n = 225) were 14 timesmore abundant than H. hippocampus (17). The mean abundance of H. guttula-tus for all the pooled sites was 0.018 m 2 (SE 0.003) ranging from a maxi-mum of 0.035 (SE 0.007) to a minimum of 0.008 (SE 0.002). The sizestructure of long-snouted seahorse shows a population ranging from 7 to14 cm (SL) with a peak at 10 cm (TL). Juveniles (96.0 8.0 mm) represent asignificant fraction of the population, accounting more than 21% of the sightedindividuals. In Mar Piccolo, H. guttulatus is able to shelter both in monoto-nous habitats, including the algal beds, and diversified ones, such as the richfilter-feeder communities that colonize hard substrates. By contrast, H. hippo-campus is mainly associated with habitats of low complexity. Today, the MarPiccolo di Taranto is among the most heavily polluted water bodies in SouthItaly, with trace metals, hydrocarbons, pesticides and organic wastes affectingboth biotic and abiotic matrices. However, despite the high level of degrada-tion, the presence of a large mussel farm has avoided the impact of towed fish-ing gears, and eutrophication of water bodies has ensured a high trophic levelthat supports large crustacean populations, potential prey for seahorses.IntroductionWorldwide, seahorse (Hippocampus Rafinesque 1810 spp.)populations and their relatives in the family Syngnathidae(pipefishes, seadragons and pipehorses) are threatened by(i) degradation of their estuarine, seagrass, mangrove andcoral habitats (Olden et al. 2007), (ii) incidental capturein fishing gear (bycatch) (Vincent 1996), and (iii) over-exploitation for use in traditional medicines and in theaquarium trade (Salin et al. 2005). Moreover, seahorseshave life histories, behaviour and ecology that make themparticularly vulnerable to population decline (Foster V Vincent et al. 2011). In addition, seahorses inhabitshallow, coastal areas worldwide, where anthropogenicdisturbances tend to be the most frequent and severe,and represent the main threat to their integrity. The

We present a data set on the biodiversity of Italian freshwaters, including lakeshores and riverbanks of natural (N=379: springs, streams and lakes) and artificial (N=11: fountains) sites. The data set belongs partly to the Italian Long Term Ecological Research network (LTER-Italy) and partly to LifeWatch, the European e-Science infrastructure for biodiversity and ecosystem research. The data included cover a time period corresponding to the last fifty years (1962-2014). They span a large number of taxa from prokaryotes and unicellular eukaryotes to vertebrates and plants, including taxa linked to the aquatic habitat in at least part of their life cycles (like immature stages of insects, amphibians, birds and vascular plants). The data set consists of 6463 occurrence data and distribution records for 1738 species. The complete data set is available in csv file format via the LifeWatch Service Centre.

The macrozoobenthic assemblage from the Karavasta lagoon system, the main wetland of Albania, was studied on soft bottoms and artificial hard substrates. Three different communities were identified: the typical ‘brackish-water community’, an ‘outlet community’ dominated by filter-feeders, and a typical ‘marine community’, inhabiting fine sandy bottoms, where polychaetes are dominant, together with a few species of tunicates and bivalves, which colonize hard substrates. The occurrence of build-ups of the bryozoan Conopeum seurati, settled on the upper portion of long submerged wooden poles, was the main feature of faunistic interest. The faunistic affinity between the zoobenthic assemblage recorded in the hyperhaline lagoon of Karavasta and the assemblages from two Italian lagoons, the brackish Lake of Lesina and the euhaline Lake of Fogliano, was considered according to the different hydrological conditions and the geographical location. Hydrological confinement and salinity were likely to be the leading factors influencing the benthic community composition in the Karavasta wetland area. Therefore, on a vaster spatial scale, the isolation and geographical proximity of the ecosystems and colonizing ability and dispersal changes of the species appear to be the main factors liable to produce faunal variations.

The present study focuses on the reproductive success of transplants of the bath sponge Spongia officinalis Linnaeus, 1759, with the aim of investigating the possibility of restocking this species, one of the most endangered organisms of the Mediterranean sessile zoobenthos. Transplants of S. officinalis, collected from a wild population along the Apulian coasts (Ionian Sea, Italy), have been moved into an area where the species was present in the past. The transplants consisted both of specimens in toto and of fragments of different sizes, obtained after having cut the mother sponge into pieces. All transplanted sponges showed complete cicatrisation of the cut surfaces within a month of the initial manipulation and had a survival rate of 100% throughout the 12 months of the study. From the present investigation, it has emerged that the reproductive effort and the larval release by the transplants do not differ significantly from those shown by the source population. This successful technical approach supports its application as a strategy for restocking the population of this endangered species.

The relevance of the budding process in a population of Tethya citrina inhabiting an unpredictable environment subjected to frequent anoxic crisis (Mar Piccolo di Taranto) is described, and new data about the fate of the buds after their release are provided. At the individual level, for the first time in natural conditions, it has been demonstrated that several budding events follow each other, alternating with short periods (1–2 months) of rest. At the population level, budding proved to be a continuous process, being detected throughout the 13 months of study, with a short summer decrease both in the frequency of budding specimens and bud density. This trend was markedly different from that reported for conspecific populations inhabiting stable environments, in which budding is a seasonal process. It is hypothesized that the sudden and unpredictable variations of the ecological conditions could be responsible for the onset of repeated budding events, thus stressing the role of environmental factors in affecting the asexual reproductive pattern. T. citrina buds, here investigated, tend to detach from the adult sponge within 7/15 days of their differentiation, a feature coherent with experimental data carried out under laboratory conditions. A significant relationship between the size/age of the post-buds and the onset of the asexual reproduction has been proved: in particular, the first budding event was observed in nine-month-old sponges, measuring about 7 mm in diameter. As reported for other demosponges, in T. citrina post-buds the growth rate was positively related to the water temperature, with a significant increase during the summer. In addition, a negative effect of the budding process on the sponge growth, is hypothesized for a post-bud subjected to repeated budding events. Growth rate, however, proved highly variable.

The macrofauna settling on experimental substrates was studied at two sites of the Lesina Lagoon to test its possible role in monitoring ecological variations in a brackish-water ecosystem. The community settlement was seasonally investigated on 3-month-old wooden poles; the development was monitored from 2001 to 2005. Comparisons with benthic assemblages settled on 10-yr-old poles were also performed. The main hydrological parameters were periodically measured during the study. A total of 38 species were collected. The assemblage reached the highest development in the central lagoon, showing relevant carbonate structures which supported a rich vagile fauna. Close to the sea-water inlet species richness and abundance values were lower, with the disappearance of some brackish-water species. A remarkable salinity drop during 2004 produced some faunistic changes in the assemblages, which however maintained different structures between the study sites, thus confirming macrozoobenthos as an efficient bioindica...

The reproductive cycle of the bath sponge Spongia officinalis L. has been studied over 1 year on 11 tagged specimens of different sizes (from 82 to 886 ml, in volume) from Ionian coasts of Apulia (SE Italy). According to literature data, the sponge is viviparous. All the monitored specimens showed sexual reproduction, even if the process usually involved small portions of the sponge tissue. Ten specimens were gonochoric (sex ratio 1:1), one specimen showed successive hermaphroditism, with alternate production of oocytes and spermatic cysts in the same reproductive season. Young oocytes occur almost all year round, whereas large mature eggs show a peak in October–November, concomitantly with the appearance of spermatic cysts. No relationships were observed between the sponge size and the presence of sexual elements within the range of the sponge size considered in this research. Embryo development occurs in patches of choanosomal tissue, which contain four or more elements. Cleavage is total and equal; it starts in November and in May leads to a solid stereoblastula, which develops into a parenchymella larva, from May to July. The stereoblastula lacks flagella and its surface is delimited by elongated cells well segregated from the internal ones. Parenchymella larvae are released from June to July, asynchronously, either at the individual or population level, with a few days of de-phasing. Up to 523 larval elements/48 h for a sponge specimen were counted. The free-swimming larvae are ovoid and uniformly flagellated. Flagella are longer at the posterior region, than on the rest of the larval body. Flagellated cells form a pseudo-stratified epithelial layer, delimiting the outermost larval surface, and are filled with electron-lucent vesicles showing a homogenous content. No choanocyte chambers, pinacocytes or skeletal elements are present in the newly released larvae.

The reproductive cycle of Geodia cydonium in a semi-enclosed Mediterranean bay (Porto Cesareo, SW Apulia) was studied with monthly frequency over a 3-year period. The investigation was carried out by uti- lizing a technique consisting of tagging ten individuals with a PVC stick and cutting oV, by means of a metal cork borer, small samples (cylinders about 5 cm 3 in vol- ume) from each of them for histological analysis. Sex- ual reproductive elements were detected in all individuals, but in the third year some specimens showed reduced reproductive activity or complete infertility. Spermatogenesis occurred in a short period (from June to August) whereas oogenesis lasted longer (from spring to late summer). Spermatic cysts occurred when the frequency of specimens with oocytes reached its maximum values. A relationship between water temperature and the onset of gamete diVerentiation was observed. G. cydonium is here conWrmed ovipa- rous and gonochoric with a sex ratio in favour of the females. However, in contrast with current literature on Porifera—which suggests that only a limited num- ber of sponges, all belonging to the same species are sexually active—the sexual reproduction of this species involves all the examined individuals. This Wnding can be explained by the methodological approach used in this research, which diVers from the traditional way of assessing the sponge reproductive cycle by analysing randomly collected specimens within a population. The study of a series of individuals over time represents a better "model technique" for investigating sponge sex- ual reproduction and the eVect of environmental parameters on gamete diVerentiation.

The present work focused on the taxonomic composition, spatial distributions, and temporal distributions of the sponge fauna from the main lagoon systems of southern Italy: Lesina, Varano, Taranto, Alimini, Faro, Ganzirri, Tindari and Marsala. Overall, 62 sponge species were recorded, belonging to the classes Demospongiae (52 species), Calcarea (8) and Homoscleromorpha (2). All the lagoon systems studied hosted sponges, even if with marked differences. Species richness varied from one (Lesina) to 45 (Marsala). A large number of the species recorded during this study (52%) was found only at a single site, whereas a species only (Halichondria (H.) panicea) was present in all the environments studied. Sponges colonised all available substrates. Salinity was the ecological factort hat best explained the spatial distribution of sponges, even though the wide heterogeneity of sponge assemblages, strongly suggests an important role of stochastic factors acting on pre- and post-settlement phases. Comparison of the present data with lists available from the literature shows that sponge assemblages from most of the studied lagoons were quite persistent. However, in some of the lagoons remarkable extinction processes, probably related to massive and prolonged anthropogenic pressures, have contributed to large changes in the sponge patterns.

Macro- and megafauna were recorded in the submarine Bari Canyon (southern Adriatic Sea, Mediterranean Sea) during an oceanographic cruise carried out in May-June 2012 and an experimental fishing survey conducted in November 2013. During the former, a total of 20 benthic samples were taken using a Van Veen grab at depths between 268 and 770 m and 4 deployments of a baited lander, for about 43 hours of video records, were carried out at depths between 443 and 788 m. During the latter, 8 longline fishing operations were conducted from 338 down to 612 m. Eighty-five living benthic and benthopelagic species were recorded: 29 Porifera, 1 Cnidaria, 2 Mollusca, 11 Annelida, 1 Arthropoda, 19 Bryozoa, 3 Echinodermata and 19 Chordata. A total of 51 species are new records for the Bari Canyon, 29 new records for the Adriatic Sea. Among the Porifera Cerbaris curvispiculifer is a new addition for the Italian Sponge Fauna. The first certain record of living specimens for the bryozoan Crisia tenella longinodata is reported. A total of 6 Mediterranean endemic species have been identified: 4 Porifera and 2 Annelida. The bathymetric range of some species has been extended. New information acquired for deep sea species confirms their importance in the structure of cold-water coral communities. This study has updated the knowledge on the biodiversity of the Adriatic Sea, as well as of the Bari Canyon in particular, one of the sites designated as “jewels of the Mediterranean” for which urgent conservation measures are needed.

The sexual and asexual phases of the reproductive cycle of the sponge Mycalecontarenii (Martens, 1824) were studied from samples collected over a period of 2 years (June 1994 to May 1996) in a Mediterranean coastal basin (Porto Cesareo, southwestern Apulia). The species is viviparous; year round it shows a discontinuous oocyte production. No males were found, possibly owing to the very short period of spermatogenesis. M.␣contarenii produces asexual buds during autumn and winter, and this process seems to be related to changes in water temperature. Even though, at present, we cannot evaluate the incidence of larval recruitment, we postulate that asexual reproduction in M.contarenii plays a crucial role in maintaining the sponge population.

A coastal red coral [Corallium rubrum (L.)] population, whose age structure and demographic parameters have been previously analysed, harbours 10 species of endobiotic sponges. This sponge assemblage differs considerably from that inhabiting other calcareous substrata of the surrounding area, suggesting some selectivity for red coral. The two most common endobiotic species, Spiroxya heteroclita Topsent and Cliona sarai Melone, are described in detail. The percentage of infested coral colonies increases according with colony age, with a sharp increment at four years. An increase in coral colony mortality observed at this age may be related to the increment of endobiotic sponge infestation.

In recent years, several episodes of mass mortality of sessile epibenthic invertebrates, including sponges, have been recorded worldwide. In the present study, we report a disease event on Ircinia variabilis recorded in September 2009 along the southern Adriatic and Ionian seas (Apulian coast), with the aim to quantify the mortality incidence on the sponge population, to investigate the effect of the disease on the sponge tissues and to assess whether the disease is associated with vibrios proliferation. The injured sponges showed wide necrotic areas on the surface or disruption of the body in several portions. Necrotic areas were whitish and often were covered with a thin mucous coat formed by bacteria. In the most affected specimens, sponge organisation resulted partial or complete loss, with the final exposure of the dense skeletal network of spongine fibres to the environment. The results of microbiological cultural analysis using in parallel Marine Agar 2216 and thiosulphate/citrate/bile salts/sucrose agar demonstrated that, in affected specimens, vibrios represented 15.8 % of the total I. variabilis surface culturable bacteria. Moreover, all the isolated vibrios, grown from the wide whitish areas that characterize the surface of the diseased sponges, were identified, and their assignment to the Vibrio rotiferianus was consistent with phylogenetic analysis and data of morphological, cultural and biochemical tests. Studies on V. rotiferianus have shown that its pathogenicity, with respect to various aquatic organisms, is higher than that of Vibrio harveyi. The factors triggering the disease outbreak in Ircinia variabilis populations remain unclear. At present, we can hypothesize the involvement in the disease of a synergetic mechanism that, under stressful physiological conditions (high temperature, elevated nutrients and reduced water flow), induces sponge pathogens, in our case V. rotiferanius, to become virulent, making sponges unable to control their proliferation. Additional studies are needed to understand the etiological processes as well as the factors involved in sponges recovering from this epidemic event allowing them to face mass mortality. A drastic reduction of sponge-specific representatives could have marked a negative impact on the environmental health on account of their role in the sea remediation processes as filter-feeding organisms.

Tethya microstella, T. orphei, T. robusta, and T. seychellensis live in sympatry in a Maldivian coral reef lagoon (Gangehi Island, Ari Atoll). A morphological, morphometric, and electrophoretical study of these species show that their Maldivian populations are well separated morphologically and genetically. The genetic distances and the other data are more consistent with an immigration than with a local speciation hypothesis. Their coexistence may be explained by a differentiation in ecological requirements. The four species inhabit the shallow water biotope of the lagoon among the rubble of dead corals. Our data show that T. orphei and T. seychellensis occupy the upper rubble layer, T. microstella and T. robusta the lower one. This distinction agrees with the different morpho-functional features of the two pairs of species.

The megasters of T. aurantium and T. citrina consist, in their mature stage, of spherasters and spheroxyasters respectively. A study of the ratio between the ray length and the diameter of the centre (R/C), which determines the megaster shape, has been carried out on spicules of different size. While the small megasters of these two species have a similar shape, successive stages show in T. aurantium an isometric growth and in T. citrina an allometric growth with rays growing faster than the centre. The two species differ also in the mean size, size frequency distribution and number of rays of the asters. Differences in the mean total diameter and shape were also detected among spicules coming from different regions of the sponge body. The taxonomic and evolutionary meaning of these phenomena are discussed.

The variations in both silica content and spicular size were studied in two populations of the demosponge Pellina semitubulosa (Lieberkuhn). Samples were collected over a period of 1 year (June 1994 to May 1995) in two Mediterranean coastal basins: Porto Cesareo (southwestern Apulia) and Marsala (northwestern Sicily). The values of spicule size (length and width) and sponge silica content were significantly higher in the population of Porto Cesareo, where the highest water silica concentration was recorded. In both Porto Cesareo and Marsala the sponge silica content showed a seasonal trend, positively correlated with water temperature values. In both populations, the smallest spicules were found in specimens collected from summer to late autumn, after sexual reproduction. Secretion of new spicules may be connected with the process of remodelling occurring in sponges after gamete and larval release.

In the Sicilian lagoon Stagnone di Marsala, Tethya aurantium and T. citrina show different ecological distributions, although some overlapping occurs. The first species reaches its highest density where linear currents are maximal, and in this habitat it is particularly frequent on Posidonia oceanica rhizomes. The second species is more abundant in still water locations and is equally common on Posidonia rhizomes and on calcareous concretions. Such distributions can be related to water movement, Posidonia shoot density, and associated factors such as sedimentation and food availability. These observations are consistent with an adaptive interpretation of the morphofunctional features distinguishing the two species.

The demosponge Tethya citrina Sarà & Melone was subjected to long-term aquarium farming, considering that several species belonging to this genus are a rich source of useful bioactive metabolites. The rearing method in the present research was mainly based on applying parameters taken from the current literature. The sponge's biological activity was assessed in terms of survival and growth over time; status of filtering apparatus; protein banding profiles. Farmed sponges showed a high survival rate and marked reduction in size. In addition, they were frequently affected by massive production of asexual buds. Histological and ultrastructural observations showed a gradual disorganization of the sponge choanocyte chambers, with a drastic reduction in choanocytes and a progressive increase in spherulous cells. Comparative electrophoretic analysis of the protein profiles of wild and reared specimens showed differences in protein composition and abundance between the tested groups. Such data are consistent with the increase in spherulous cells whose content was markedly electron-dense, a feature stressing the proteinaceous nature of these inclusions. Experimental tank-rearing of Tethya provided promising responses in terms of high survival rate of the species and easy reproduction, though the rearing protocol used led to profound morpho-functional changes in the sponge. This confirms the inadequate state of knowledge on farming techniques for this taxon, while also highlighting potential applications in biotechnology of ex situ breeding techniques, in order to modify the sponges' biological responses.

The sexual and asexual phases of reproductive cycles of two sponges, Tethya citrina and T. aurantium, living sympatrically in a Mediterranean coastal lagoon (Stagnone di Marsala, NW Sicily) were studied from samples collected over an 18-mo period. Both species are oviparous and gonochoric. They have a summer, partially overlapping, period of oocyte production, although T. citrina appear to mature earlier. No males were found, possibly due to the very short period of spermatogenesis. Both species produce asexual buds during the autumn/winter months. However, they seem to follow different reproductive strategies, with T. citrina showing a significantly lower production of buds than T. aurantium; by contrast, egg production is significantly lower in the latter species. The difference in the reproductive resource allocation is consistent with data reported in the literature on the anatomy features, genetic population structure and ecological distribution.