TUBE MORPHOLOGY AND STRUCTURE OF THE BATHYAL MEDITERRANEAN SERPULID HYALOPOMATUS VARIORUGOSUS BEN-ELIAHU & FIEGE, 1996 (ANNELIDA, POLYCHAETA)

The species studied differs from the other Hyalopomatus species by having a peculiar rugose sculptured outer tube surface. This character is markedly variable; it can be more or less developed and may also vary along the same tube. Observed by SEM, this rugosity proves to consist of irregular flaps, roughly following the growth lines. SEM observations on transverse fractures show a homogeneous composition of the tube wall, consisting of calcium carbonate crystals. These crystals show a prismatic habitus and are arranged in a homogeneous granular microcrystalline structure. New records of H. variorugosus are from deep water stations in the Western Mediterranean and from Pleistocene bathyal deposits of Southern Italy. The discussion covers aspects of tube characters of use for taxonomy. 

Cemented on the Rock. A Pleistocene Outer Shelf Lithobiont Community from Sicily, Italy

The lithobiont community encrusting an early Pleistocene palaeocliff cropping out north of Augusta (SE Sicily, Italy) was investigated based on field observations and laboratory inspection of two rocky samples. Bryozoans, serpulids, brachiopods and bivalves encrusted part of the exposed surfaces that were bored mostly by clionaid sponges. Bryozoans, with at least 25 species detected on the rocky samples, are the most diversified skeletonized lithobionts also accounting for the highest number of colonies/specimens and highest coverage. Brachiopods, with the only species Novocrania anomala and a few but large cemented valves, cover wide surfaces. Serpulids, with two species identified on the sampled rocks and further two on the outcrop, were intermediate. A multiphase colonization is present, including a final epilithobiont community locally formed on eroded surfaces exposing a network of pervasive borings. The co-occurrence of very sciaphilic species having circalittoral to bathyal distributions suggests that the studied community thrived on a rocky substratum located near or at the shelf break, probably belonging to the shelf break (or RL) biocoenosis, also in agreement with observations on the fossil content of neighboring marly sediments. The observed relationships among colonizers largely represent mere superimpositions, and real interactions are not enough to state species competitiveness

BRYOZOANS AS SEDIMENTARY INSTABILITY INDICATORS

In several Neogene stratigraphic sections of Italy bearing bryozoan assemblages, a great dominance of lunulitiform bryozoans was recorded in those levels characterized by the abundant muddy fraction of the sediment, and by the presence of Heterogeneous Communities. These latter settle and quickly evolve on sea-floors where anomalous sedimentation rates occur, caused by climatic or tectonic factors. Research carried out so far shows that lunulitiform bryozoans may be regarded as insrabiliry indicators, characterizing the early phase of Hererogeneous Communities

First record of sabellid and serpulid polychaetes from the Permian of Sicily

Some tubular fossils attributable to sabellids and serpulids, and a serpulid operculum are described for the first time from the Wordian to upper Permian “Pietra di Salomone”, “Rupe di San Calogero”, and “Rupe di San Benedetto” limestones (Sosio Valley, western Sicily, Italy). Tubes are attached to skeletons of sponges, crinoids, brachiopods and stromatoporoids. The material consists of about twenty incomplete tubes (attached and free portions) and includes some small tubes, ca. 0.2 mm wide, belonging to the sabellid Glomerula (with the species G. testatrix comb. nov. and G. gemmellaroi sp. nov.), the serpulid Filograna sp., and large-sized tubes, up to 3 mm wide, belonging to three newly described serpulids: Propomatoceros permianus sp. nov., “Serpula” distefanoi sp. nov., and Serpulidae sp. indet. They are triangular or circular in cross-sections, and display growth lines and/or ornamentations (keels or ribs) on their outer surfaces. Furthermore, an opercular cup referable to those assigned to the genus Pyrgopolon, is also described under the name P. gaiae sp. nov. All specimens show large secondary calcite crystals in their tubes, the original structure being biased by diagenesis. Material represents the first evidence of genuine calcareous tube-dwelling polychaetes from the Palaeozoic, and possibly so far unknown ancestral representatives of the families Sabellidae and Serpulidae. The tubeworm association together with the invertebrates upon which they settled, presumably lived in an exposed shallow- water palaeoenvironment, at the outer edge of a carbonate platform

New serpulid polychaetes from the Permian of western Sicily

Two new tubeworms, “Serpula” calannai sp. nov. and “Serpula” prisca sp. nov. are described from the Permian limestone of the Sosio Valley, western Sicily. Both species possess large tubes with long free anterior portions circular in cross-section. All morphological characters, such as tube shape and ornamentation, as well as inner structure of the wall, even if barely visible due to diagenesis, are still preserved. These two new species increase the previously known diversity of the Permian serpulid community, which flourished at the shelf edge of the western sector of the Palaeotethys and disappeared thereafter. The likely Wordian age of these serpulids, and their presumed absence in younger rocks up to the Middle–Late Triassic, suggests reduction, or even extinction, of these reef-related serpulid taxa during the end-Guadalupian biotic crisis, before the end-Permian extinction

Degradation of a photophilic algal community and its associated fauna from eastern Sicily (Mediterranean Sea)

The status of the "Biocoenosis of the Infralittoral Algae" of the upper infralittoral zone (at 5 m depth) from two selected stations along the eastern coast of Sicily (Ionian Sea, Mediterranean) was studied with a multiproxy approach involving the study of algae and associated protist and animal organisms, including foraminifers, serpulids, molluscs, bryozoans and ostracods. Scraped samples (40x40 cm) were collected at selected seasons during a 2-year period (2015-2016) in order to identify possible seasonal and spatial differences between the two stations, and to compare present data with historical ones. A community made up of the algae Halopteris scoparia, Padina pavonica, Dictyota dichotoma, Ellisolandia elongata and several other geniculate coralline algae was found in sites historically colonised by a Cystoseira brachycarpa community, which was not found during our study. These algae presently structure the community and provide substratum for several associated epibiotic species. Hierarchical cluster analysis and Non-Metric Multi-Dimensional Scaling Ordination significantly differentiate the communities between the two stations but show no clear seasonal trend. Differences largely relate to changes in the algal vegetation and the impact produced by the regression of structuring species on epibiots (especially serpulids and bryozoans). Comparison with historical algal data from the area indicates the disappearance of Cystoseira brachycarpa, which was present at least until the last '1990s, and a community degradation with a considerable loss in species richness. This parallels observations in other Mediterranean areas, and could be related to the increase in echinoid population density and their heavy grazing activity

Palaeohistology reveals a slow pace of life for the dwarfed Sicilian elephant

Altres ajuts: CERCA Programme/Generalitat de CatalunyaThe 1-m-tall dwarf elephant Palaeoloxodon falconeri from the Pleistocene of Sicily (Italy) is an extreme example of insular dwarfism and epitomizes the Island Rule. Based on scaling of life-history (LH) traits with body mass, P. falconeri is widely considered to be 'r-selected' by truncation of the growth period, associated with an early onset of reproduction and an abbreviated lifespan. These conjectures are, however, at odds with predictions from LH models for adaptive shifts in body size on islands. To settle the LH strategy of P. falconeri, we used bone, molar, and tusk histology to infer growth rates, age at first reproduction, and longevity. Our results from all approaches are congruent and provide evidence that the insular dwarf elephant grew at very slow rates over an extended period; attained maturity at the age of 15 years; and had a minimum lifespan of 68 years. This surpasses not only the values predicted from body mass but even those of both its giant sister taxon (P. antiquus) and its large mainland cousin (L. africana). The suite of LH traits of P. falconeri is consistent with the LH data hitherto inferred for other dwarfed insular mammals. P. falconeri, thus, not only epitomizes the Island Rule but it can also be viewed as a paradigm of evolutionary change towards a slow LH that accompanies the process of dwarfing in insular mammals

Draft Guidelines for Inventoring and Monitoring of Dark Habitats

UNEP(DEPI)/MED WG. 431/Inf.12Dark habitats1 are distributed throughout the Mediterranean basin from the sea surface (i.e. caves) to the deep-sea realm. Various habitats of unique scientific and conservation interest are included in this broad habitat category, such as dark caves, submarine canyons, seamounts and chemo-synthetic features supporting sensitive assemblages which require special protection. Therefore, dark habitats were considered under the Action Plan adopted in the Eighteenth Ordinary Meeting of the Contracting Parties to the Barcelona Convention (Turkey, December 2013). In the context of implementation schedule of the Dark Habitats Action Plan (UNEP-MAP-RAC/SPA, 2015a) a set of guidelines should be identified aiming to reduce the imminent pressures and threats affecting these vulnerable assemblages. This document aims to establish guidelines for inventorying and monitoring Mediterranean deep-sea habitats and marine caves in order to settle the basis for a regional-based assessment

Unpublished Mediterranean records of marine alien and cryptogenic species

Good datasets of geo-referenced records of alien species are a prerequisite for assessing the spatio-temporal dynamics of biological invasions, their invasive potential, and the magnitude of their impacts. However, with the exception of first records on a country level or wider regions, observations of species presence tend to remain unpublished, buried in scattered repositories or in the personal databases of experts. Through an initiative to collect, harmonize and make such unpublished data for marine alien and cryptogenic species in the Mediterranean Sea available, a large dataset comprising 5376 records was created. It includes records of 239 alien or cryptogenic taxa (192 Animalia, 24 Plantae, 23 Chromista) from 19 countries surrounding the Mediterranean Sea. In terms of records, the most reported Phyla in descending order were Chordata, Mollusca, Chlorophyta, Arthropoda, and Rhodophyta. The most recorded species was Caulerpa cylindracea, followed by Siganus luridus, Magallana sp. (cf. gigas or angulata) and Pterois miles. The dataset includes records from 1972 to 2020, with the highest number of records observed in 2018. Among the records of the dataset, Dictyota acutiloba is a first record for the Mediterranean Sea. Nine first country records are also included: the alga Caulerpa taxifolia var. distichophylla, the cube boxfish Ostracion cubicus, and the cleaner shrimp Urocaridella pulchella from Israel; the sponge Paraleucilla magna from Libya and Slovenia; the lumpfish Cyclopterus lumpus from Cyprus; the bryozoan Celleporaria vermiformis and the polychaetes Prionospio depauperata and Notomastus aberans from Malta