Ionian Coast Of Apulia Research Articles

The Queen Is Dead, Long Live the Queen: The Vanishing of Pinna nobilis and the Onset of the Congeneric P. rudis (Mollusca: Bivalvia)

The bivalve mollusc Pinna nobilis, endemic to the Mediterranean Sea, has been vanishing since 2016 from the whole basin because of an infection by multiple pathogens that caused mass mortality events. In the Eastern Mediterranean, some small populations seem to be resistant to the infection. These individuals could represent the only possibility for the species to recolonize desert habitats. Thus, according to the recommendations of IUCN, looking for living specimens of P. nobilis is a priority. With this goal in mind, we carried out surveys in different areas of Southern Italy, and in 2018, we launched a Citizen Science campaign to involve recreational and professional divers in this challenge. As a result of a monitoring activity carried out in 2022–2024, along the Ionian coast of Apulia, in Southern Italy, we can say that there are no more living specimens there but only empty shells. Concurrent to the vanishing of the queen P. nobilis, its congeneric P. rudis, resistant to the infection, seems to be taking advantage, becoming more common and colonizing habitats once exclusive to P. nobilis. In fact, from different areas of the Mediterranean, sightings of the new possible queen, P. rudis, are increasing, together with the discovery of individuals exhibiting morphological traits that are a mixture of the two species. In some cases, these morphological features are not easy to detect; nevertheless, the presence of these hybrids, resistant to the infection, is important for the conservation of the species.

Holocene Sea Level Recorded by Beach Rocks at Ionian Coasts of Apulia (Italy)

Beach rocks are located along many coasts of the Mediterranean basin. The early diagenesis environment and the mean sea level along the shoreline make these landforms useful in the reconstruction of relative sea-level changes and, in particular, as SLIPs (sea-level index points). The beach rocks surveyed along the Ionian coast of Apulia were found to be well preserved at three specific depth ranges: 6–9 m, 3–4 m, and from the foreshore to about 1.20 m. Morpho-bathymetric and dive surveys were performed to assess both the geometries and the extension of the submerged beach rocks. Samples were collected at these different depths in the localities of Lido Torretta, Campomarino di Maruggio, San Pietro in Bevagna, and Porto Cesareo. Bivalve shells were identified and isolated from the beach rock samples collected at a depth of 7 m; AMS dating provided a calibrated age of about 7.8 ka BP. Their morphology and petrological features, along with the time constraints, enabled us to (i) reconstruct the local sea-level curve during the Holocene, (ii) corroborate acquired knowledge of the relative sea-level history, and (iii) identify possible local vertical land movement (VLM).

“New Mediterranean Biodiversity Records” (March 2017)

This Collective Article presents information on 22 species belonging to 5 Phyla, arranged geographically from from west to east. The new records were found in 8 countries as follows: Spain: first record of the two scarcely known nemerteans Baseodiscus delineatus and Notospermus geniculatus in Formentera; Malta: second record of the alien fish Lagocephalus sceleratus; Italy: the alien polychaete Syllis pectinans and the isopod Paranthura japonica, as well as the cryptogenic opisthobranch Anteaeolidiella lurana, were found in the fouling assemblages along the docks of the port of Livorno. New decapod records are reported from Sicily (the alien Callinectes sapidus and the native Pachygrapsus maurus) and Apulia (Percnon gibbosus and Procambarus clarkii); the lesser amberjack Seriola fasciata extended its geographical range to the Egadi Isands and Siganus luridus was documented for the first time along the Ionian coasts of Apulia and Calabria. Slovenia: the first record of the alien bivalve Brachidontes pharaonis is reported, together with a survey of up to date Adriatic records. Greece: the first record of the gastropod Rhinoclavis kochi is reported from Gavdos island. In addition, two records of endangered and rare cartilaginous fish were reported, namely, the shark Hexanchus griseus and the ray Leucoraja fullonica, as well as additional records of Siganus luridus for Lesvos and Malleus regula and Fulvia fragilis from Astypalaia. Turkey: the black wing flyingfish Hirundichthys rondeletii is reported for the very first time from the Black Sea. Egypt: the Indo-Pacific crab Halimede ochtodes is reported as established in Port Said. In addition, biometric parameters and meristic counts are reported for Anthias anthias in Damietta. Cyprus: the alien opisthobranch gastropod Bursatella leachii is reported for first time.

Evidence of relative sea level rise along the coasts of central Apulia (Italy) during the late Holocene via maritime archaeological indicators

We investigated archaeological sites located along the coasts of central Apulia (Italy) to estimate the relative sea level changes which have occurred in this region since the Bronze Age, and test the most recent model of predicted sea level for this region. Surveys focused on six sites located on both the Adriatic and Ionian coasts of Apulia at the feet of the carbonatic Murge plateau, a tectonically stable zone as of the last 125 ka. The sites present the remains of ancient settlements, ranging from the Bronze Age (circa II millennium BC), to the Messapian and Magna Grecia Age (c. 2.5 ka BP), the Roman (c. 2 ka BP) and Middle Ages (c. 1 ka BP). The archaeological sea level markers investigated in these sites provided new insight into the history of the relative sea level changes which have occurred in this region during the last c. 3.3 ka BP. Data from 17 archaeological settlements from the above-mentioned sites, placed above or below the present sea level, were analyzed. The intervening relative sea level changes successive to their construction were estimated via the submergence of the functional elevations of significant architectural features related to the mean sea level at the time during which the settlements were functioning. The r.s.l. changes were estimated using detailed topographic surveys, tide analyses and/or hydrodynamic equations. Although not all archaeological markers allowed univocal interpretations, r.s.l. rise at about 2.25 ± 0.20 m as of the Bronze Age, and at least 0.90 ± 0.20 m in the last 2.0/1.5 ka was estimated. A comparison between the elevation of the marker and two different predicted sea level models seems to confirm a tectonic stability of the investigated region in the last c. 3.3 ka BP.

Sexual reproduction, larval development and release in Spongia officinalis L. (Porifera, Demospongiae) from the Apulian coast

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.

Morphology of Xenodasys (Gastrotricha): the first species from the Mediterranean Sea and the establishment of Chordodasiopsis gen. nov. and Xenodasyidae fam. nov.

During a survey of the Italian marine meiofauna, several specimens of the rare gastrotrich genus Xenodasys were found in a submarine cave along the Ionian coast of Apulia. The finding represents the first record of the genus for the Mediterranean Sea and reinforces the consideration of marine caves as habitats of high naturalistic value. The specimens, analysed using different microscopy techniques, showed a new species, named Xenodasys eknomios. Scanning electron microscopy, unveiling the astonishing morphology of this unusual gastrotrich, indicates that, due to technical artefacts, light microscopy may generate unreal features, which in the past may have led to the misinterpretation of the anatomical traits of these creatures. Transmission electron microscopy indicated that the ‘Seitenfüsschen’, are genuine elements of the adhesive apparatus, in contrast with previous investigation, which attributed an exclusive sensorial function to these organs. Confocal laser scanning microscopy, combined with actin-binding fluorochromes, revealed muscular elements in a region where originally the muscular chordoid organ was reported for gastrotrich species belonging to the genus Chordodasys. A taxonomic revision of the species currently allocated to the genus Xenodasys led to the establishment of Chordodasiopsis gen. nov. to integrate the former Xenodasys (=Chordodasys) antennatus and to the drafting of emended diagnosis of the genus Xenodasys. An overview of the high-rank systematization of these genera is also provided, with the establishment of Xenodasyidae fam. nov. to allocate both Xenodasys and Chordodasiopsis.

Meiofauna densities and gastrotrich community composition in a Mediterranean sea cave

During the past 5 decades, the large-sized biota inhabiting dark marine caves has attracted the attention of many marine biologists; in contrast, studies concerning the meiofaunal organisms of these peculiar biotopes remain scanty and mostly with a taxonomic aim. In this study, the nature and abundance of meiofaunal taxa living in a Mediterranean, semi-submerged sea cave was surveyed in relation to distance from the entrance and over two different seasonal periods. Particular attention was paid to the Gastrotricha taxocene. Research was carried out in a cave along the Ionian coast of Apulia (southern Italy), the “Grotta Piccola del Ciolo” which opens for approximately 120 m on the north-eastern side of a shallow fjord and has a bottom blanketed by fine to very fine sand, occasionally rich in detritus. Quantitative samples in four replicates were collected by SCUBA diving, in November 2000 and June 2001, coring the sediment with a hand-held piston corer in three light-free sites (stations 1–3) located at increasing distances from the entrance. At each site, two additional 500-ml sediment samples were collected for an in vivo study of the Gastrotricha. Faunistic analysis found a fairly high meiobenthic diversity, identifying representatives of more than 12 major groups, with total abundances ranging from 656 ind./10 cm2 (10 cm2) in November to 1,069 ind./10 cm2 in June. Station 1, the closest to the entrance invariably hosted the most abundant meiofaunal community (851 ind./10 cm2 in November and 1932 ind./10 cm2 in June), followed by station 2 or 3 depending on the season. While nematodes and harpacticoids appear as the most abundant taxa when the cave is considered as a whole, other taxa may prevail numerically in selected stations, e.g. priapulids, which are the second most abundant taxon at station 1 (30 ind./10 cm2 in November and 83 ind./10 cm2 in June). Although the density of total meiofauna and that of the single groups may not be very high, the cave is interesting by virtue of the peculiarity of the hosted fauna, e.g., species and genera new to science or new to the Mediterranean Sea. Regarding the Gastrotricha, we found 16 species, accounting for 1.3–2.6% of the total meiobenthos (density = 8.4 ind./10 cm2 in November and 27.4 ind./10 cm2 in June). Analysis of the gastrotrich community found, particularly in June, an assemblage of taxa quite different from those found in open habitats, even at the family level; differences that are probably due to the exploitation of different food resources by animals populating the two environments, i.e. algae in the open sea versus bacteria in the caves. Results indicate that for meiofauna, as happens for macrofauna, the marine caves may represent hotspots of biodiversity and endemism; the driving forces at the base of the trophic depletion hypothesis seem to be responsible for structuring the meiofauna community inside the cave.

Rearing performance of Spongia officinalis on suspended ropes off the Southern Italian Coast (Central Mediterranean Sea)

The availability of bath sponges has been recently reduced due to the depletion of natural banks due to the high fishing pressure together with some local epidemic events. At present, the commercial supply is far below the demand. The main purpose of this work was to estimate the rearing performance of Spongia officinalis var. adriatica, one of the most common Mediterranean commercial sponges, testing two different variants of culture on suspended ropes: a horizontal system placed close to the seabed, and a vertical system extended along the water column. The trials were carried out in Southern Italy (Ionian coast of Apulia, Central Mediterranean) from April 1997 to April 2000. Wild specimens of sponge were cut into pieces of different weight to test possible differences in growth and survival. During the study period, both systems resisted deterioration due to water movement and other ecological factors. In general, the growth performance (average weight, specific growth rate) did not significantly vary between the cultivation systems, nor were statistical differences in growth detected between the cuttings of different initial size. The mean growth observed was rather variable among sponge cuttings, even considering the same rearing condition and size range. The measured variations of hydrological parameters did not seem to affect survival, growth performance, or reproductive activity, which was detected almost all year round. Larger explants (about 50 g in wet weight) reached the commercial size after three years of rearing, thus identifying this initial size as the most suitable for cultivation purposes. At the end of the study period, the survival rate was 75%, with a more apparent decrease during the first year of rearing.

A new meiobenthic priapulid (Priapulida, Tubiluchidae) from a Mediterranean submarine cave

A new priapulid species belonging to genus Tubiluchus is described on the basis of specimens collected in November, 2000 and June, 2001 in a submarine cave along the Ionian coast of Apulia, Southern Italy. The new species closely resembles T. corallicola that inhabits the tropical‐subtropical areas of the Western Atlantic Ocean but can be distinguished by the smaller size of the adults, and the smaller size and the shape of the pharyngeal teeth of the larval stages. A careful microscopical survey of the sensorial elements led to the discovery of a central bristle in the flosculi and a small hole at the tip of the associated setae, allowing speculation about a tactile sensorial function for the former and a chemoreceptive function for the latter. While T. troglodytes n. sp. represents the first fully described species of this genus from the Mediterranean Sea, the population densities recorded, particularly those found in June, 2001 (83.8 ± 40.1 SD ind./10 cm2) rank among the highest value reported for priapulids from any location in the world. On both sampling dates the sex ratio (female/total adults) in the T. troglodytes n. sp. population averaged about 0.6. Presence of larval stages of different ages during both sampling periods could imply that Tubiluchus spp reproduce the year around.

Persistent contaminants in dolphins: an indication of chemical pollution in the Mediterranean Sea

Concentrations of metals (mercury and methylmercury, selenium, cadmium, lead), chlorinated pesticides and polychlorinated byphenyls (PCB) have been determined in tissues and organs of Stenella coeruleoalba dolphins beached along the Adriatic and Ionian coasts of Apulia (Southern Italy). The results obtained confirm that in Mediterranean dolphins the accumulation of contaminants is higher than in similar species living in the Atlantic. Therefore cetaceans can be considered “organisms indicating pollution”. Accumulation is influenced by factors such as diet, age and sex. Reproduction plays a fundamental role in the elimination of toxic compounds in females. Correlation between contamination and death has not been found; however it is clear that pollutants at sub-lethal doses have neuro-toxic effects, increase stress and alter immune defences, leaving the organism at a greater risk from disease.

Persistent contaminants in dolphins: An indication of chemical pollution in the mediterranean sea

Concentrations of metals (mercury and methylmercury, selenium, cadmium, lead), chlorinated pesticides and polychlorinated byphenyls (PCB) have been determined in tissues and organs of Stenella coeruleoalba dolphins beached along the Adriatic and Ionian coasts of Apulia (Southern Italy). The results obtained confirm that in Mediterranean dolphins the accumulation of contaminants is higher than in similar species living in the Atlantic. Therefore cetaceans can be considered “organisms indicating pollution”. Accumulation is influenced by factors such as diet, age and sex. Reproduction plays a fundamental role in the elimination of toxic compounds in females. Correlation between contamination and death has not been found; however it is clear that pollutants at sub-lethal doses have neurotoxic effects, increase stress and alter immune defences, leaving the organism at a greater risk from disease.

Speciation of mercury in dolphin liver: A two-stage mechanism for the demethylation accumulation process and role of selenium

Liver samples of Stenella coeruleoalba dolphins, beached along the Adriatic and Ionian coasts of Apulia (southern Italy), have been analysed for their mercury, methyl mercury and selenium contents. Clear experimental evidence is provided for the existence of a two-stage mechanism for the demethylation/accumulation process of mercury in dolphin liver, as well as a threshold Hg level ( ca 100 μg Hg/g) above which co-accumulation of selenium occurs. Only above the threshold is a 1:1 molar ratio observed between selenium and mercury fraction not released by an acid hydrolysis step at room temperature. The existence of HCl soluble inorganic compounds such as mercury selenite or selenate could be excluded. Different binding sites can be hypothesized for mercury, based on the evidence that different amounts of the metal were recovered depending on the particular physico-chemical treatment of the liver sample. The demethylation/accumulation process of mercury probably involves the formation of HgSe and selenocompounds with Se containing residues of specific proteins.

Human predation along Apulian rocky coasts (SE Italy): desertification caused by Lithophaga litho-phaga (Mollusca) fisheries

The date mussel Lithophaga lithophaga is a Mediterranean boring mollusc living in calcareous rocks. Its populations are intensely exploited by SCUBA divers, especially in southern Italy. Collection is carried out by demolition of the rocky substratum, so that human predation on date mussels causes the disappearance of the whole benthic community. The impact of this activity along the Apulian coast was evaluated by 2 surveys carried out by SCUBA diving inspection of the Salento peninsula. The Ionian coast of Apulia, from Taranto to Torre dell'Orso (Otranto), was surveyed in 1990 and in 1992 by 2 series of transects (from 0 to 10 m depth, 2 km from each other), covering 210 km. Observations were transformed into an index of damage, ranging from 0 (no damage) to 1 (complete desertification). 159 km of the inspected coast are rocky. The first survey (1990) allowed us to estimate that a'total of 44 km was heavily affected by this human activity (the index of damage ranging between 0.5 and l), whereas the second survey showed heavy damage along a total of 59 km. This increase in length was accompanied by a high increase in the index of damage along parts of coast that were less intensely exploited in 1990 than in 1992. The second survey (1992) was extended to 90 km of the Adriatic coast of Apulia (from Otranto to Torre S. Sabina, Brindisi), with 43 km of rocky coast and a total of 10 km heavily affected by date mussel fishery. Date mussel collection is one of the most destructive human activities along the Apulian coast and it has long-term effects because sea urchin grazing probably prevents recolonization of barren areas. Rarefaction of the resource due to overexploitation and habitat destruction caused rapid 'evolution' of the techniques of predation, with an increase in searching efficiency achieved by the use of underwater vehicles. Similar impacts of date musselco1- lection have been recorded in other parts of the Italian coast, especially Campania and Sardinia, and it is possible that such situations are common, but still undetected, in other areas of the Mediterranean.