Gianfranco Sartoni

A comparative study of the red alga Grateloupia filicina (Halymeniaceae) from the Northwestern Pacific and Mediterranean with the description of Grateloupia asiatica, sp. nov.

Morphological observations and molecular analyses of the red alga Grateloupia filicina (Halymeniaceae) from two geographically distant regions, eastern Asia (Japan and northern China) in the northwestern Pacific and Italy in the Mediterranean, reveal the presence of two distinct entities. Morphologically, the eastern Asian entity differs substantially from the Italian entity in the following ways: 1) thin and soft thalli with wider axes, 2) denser medullary filaments, 3) scattered reproductive structures over the entire thallus, and 4) a mature auxiliary cell that is oval and slightly larger than other ampullary cells. Phylogenetic analysis based on the ribulose‐1,5‐bisphosphate carboxylase/oxygenase gene (rbcL) sequences revealed that the eastern Asian and Italian entities are phylogenetically far apart, strongly supporting the differentiation of these two entities at the species level. The eastern Asian entity is therefore described as a new species, Grateloupia asiatica. This species can be distinguished from most known species of Grateloupia that have widely flattened thalli by its compressed to narrowly flattened axes with numerous pinnate proliferations and from a few species with similar thalli by a particular combination of features, including a gelatinous texture, mostly simple and narrower axes, a thinner cortex, and the absence of catenate proliferations.

A survey of the marine algae of Milos Island, Greece

Abstract The composition of the benthic macroflora was studied in an area of shallow-water gas-hydrothermal vents in the Palaeochori Bay (Milos Island, Aegean Sea). Some species, both taxonomically and biogeographically remarkable, were collected Tribonema marinum J. Feldmann, Stypopodium schimperi (Buchinger ex Kutzing) Verlaque et Boudouresque, Amphiroa rubra (Philippi) Woelkerling, Cutleria cf. chilosa (Falkenberg) Suva, Womersleyella setacea (Hollenberg) R.E. Norris). The large number of species with warm-water affinities [Halopithys incurva (Hudson) Batters, Jania adhaerens Lamouroux, Laurencia microcladia Kutzing, Tricleocarpa fragilis (Linnaeus) Huisman et Townsend, Stypopodium schimperi (Buchinger ex Kutzing) Verlaque et Boudouresque, Zonaria toumefortii (Lamouroux) Montagne, Anadyomene stellata (Wulfen) C. Agardh, Dasycladus vermicularis (Scopoli) Krasser, Microdictyon tenuius Decaisne ex J. Gray] is mainly due to the southern location of the Milos Island but could be also related to a homogeneous influence of vent activity throughout the bay.

Paulsilvella huveorum gen. & sp. nov. (Corallinaceae, Rhodophyta) from the Holocene of Somalia and Kenya, with a reassessment of Lithothrix antiqua from the Late Pleistocene of Mauritius‡

Abstract A morphological, anatomical and taxonomic account of Paulsilvella Woelkeriing, Sartoni & Boddi gen. nov. (Corallinales, Rhodophyta) is provided. Paulsilvella belongs to the Corallinaceae, subfamily Lithophylloideae sensu lato (encompassing the Amphiroideae) and differs from other lithophylloid genera (Amphiroa, Ezo, the Lithophyllum-Titanoderma complex, Lithothrix, Tenarea) in possessing nongeniculate protuberant branches that resemble a series of fused beads. The branches are entirely monomerous, with a core region composed of single arching tiers of elongate, columnar cells alternating with two tiers of short, noncolumnar cells. Paulsilvella includes one known extant species, P. huveorum Woelkerling, Sartoni & Boddi sp. nov. from Somalia and Kenya, and one known fossil species, P. antiqua (G.F. Elliott) Woelkerling, Sartoni & Boddi comb. nov. from the Late Pleistocene of Mauritius. The latter was originally described as Lithothrix antiqua (‘antiquum’). In P. huveorum, the uniporate carposporangial and tetrasporangial conceptacle chambers are largely buried within the thallus, whereas in P. antiqua they protrude above the surrounding thallus surface. A key to species is provided, and generic relationships within the Lithophylloideae are discussed.

Studio preliminare sulla tipologia della vegetazione sommersa del Canale di Sicilia e isole vicine

Abstract Preliminary studies on the marine phythobenthic communities in the Straits of Sicily and adjacent islands. — The results of algological researches carried out by the Gruppo di Algologia of the S.B.I. in the Straits of Sicily and adjacent islands are reported. 288 species have been collected, 275 of which have been identified: 160 were Rhodophyta, 62 Phaeophyta, 32 Chlorophyta, 16 Cyanophyta and 2 Angiospermae. The vegetational research leads to the following conclusions: 1 - the harbour areas (Pantelleria, Malta: loc. 1 and 11) show a nitrophile vegetation, particulary near La Valletta where an almost pure population of Pterocladia pinnata is found; 2 - there are important biogeographical differences between Pelagie islands (Lampedusa, Linosa) and Pantelleria. In fact the former ones have an algal flora composed mostly of eastern mediterranean species, whilst the latter shows strong affinities with the north-african basin, as is demonstrated by the rich well developed belt of Cystoseira sedoides;...

Contributo alla conoscenza della flora algale bentonica di Sar Uanle (Somalia meridionale)

Abstract Contribution to the study of the marine algae of Sar Uanle (Southern Somalia). – Some preliminary researches have been carried out on the algal flora of Sar Uanle, lying south of Chisimaio in southern Somalia. The material first collected for these researches, that includes 69 species, appears mainly new for the Somalia coasts. This is due to the fact that the bibliography concerning this part of the western Indian ocean is very scarce. The presence of a remarkable percentage of species that are widely distributed in the indo-malaysian area, has been found out through the results of these enquiries.

Ultrastructure of vegetative and motile cells, and zoosporogenesis in Chrysonephos lewisii (Taylor) Taylor (Sarcinochrysidales, Pelagophyceae) in relation to taxonomy

Ultrastructural observations on the vegetative filaments, motile cells and processes leading to zoospore differentiation in Chrysonephos lewisii are presented. Vegetative filaments are embedded in a mucilaginous envelope, preserved by Alcian blue fixation, which favours their aggregation and also the attachment of bacteria, diatoms and various types of debris. The filaments are provided with an external wall consisting of microfibrils positive to the PATAg test and ConA-colloidal gold labelling. Inside the filaments the vegetative cells differentiate into zoospores. This accounts for the ultrastructural similarity between vegetative cells and zoospores, although zoospores are typically provided with a flagellar apparatus. They share an external cell covering or theca, vacuolar or cytoplasmic ‘scale-like structures’, protruding stalked pyrenoids, scattered nucleoids of plastid DNA and absence of a photoreceptor-eyespot complex. The flagellar apparatus of zoospores is characterized by two distinct basal pla...

Comparative morphology and systematics of Chondrymenia lobata from the Mediterranean Sea and a phylogeny of the Chondrymeniaceae fam. nov. (Rhodophyta) based on rbcL sequence analyses

The Chondrymeniaceae Rodríguez-Prieto, G. Sartoni, S.-M. Lin & Hommersand, fam. nov., is proposed for Chondrymenia lobata. Analyses of rbcL sequences place the new family in a large gigartinalean assemblage that comprises the Cystocloniaceae–Solieriaceae complex. Plants are decumbent and growth takes place by division of multiple apical cells at the margin of the blade. Thalli consist of an outer cortex of subspherical to elongate cortical cells arranged in anticlinal rows, a subcortex of cells cross-linked by lateral arms, and a large central medulla composed of primary medullary filaments intermixed with numerous rhizoidal filaments. Male stages are reported in monoecious individuals. Inactive carpogonial branches consist of a two-celled filament that is directed inwards from the supporting cell. Functional carpogonial branches are oriented outwardly, with the carpogonia and trichogynes pointed towards the thallus surface. After presumed fertilization, the carpogonium fuses with the hypogynous cell and transfers the zygote nucleus. The hypogynous cell, in turn, fuses with the supporting cell which contains many haploid nuclei. The resulting fusion cell functions as an auxiliary cell that cuts off a single gonimoblast initial, which produces the gonimoblast filaments. Gametophytic cells close to the auxiliary cell unite with it to form a placental fusion network of variable size and outline, and a placental fusion cell. Proximal gonimoblast cells fuse with the placental fusion cell, while the distal cells differentiate into branched chains of subspherical carposporangia. The superficial similarity of the outwardly developed osteolate cystocarp is responsible for Kylins (1956) placement of Chondrymenia in his family Sarcodiaceae; however, the manner in which the placenta is formed is more like that seen in the Cystocloniaceae–Solieriaceae complex.

RESEARCHES ON THE COAST OF SOMALIA. THE SHORE AND DUNE OF SAR UANLE

SUMMARY The 69 species found in a recent study of the benthonic algae at Sar Uanle, South of Chisimaio, in southern Somalia are listed. Many species are reported for the first time for Somalia because there have been few studies of this region of the western Indian Ocean. A considerable number of the species found are widely distributed in the Indo-Malaysian area.

Morphological observations on some fleshy crustose algae of the Island of Gorgona (Tuscan Archipelago)

Abstract Morphological and ecological observations on four fleshy crustose algae collected in the eulittoral and upper sublittoral zone of the Island of Gorgona: Myrionema liechtenstenii Hauck, Hildenbrandia canariensis B⊘rgesen, Peyssonnelia armorica (P. et H. Crouan) Weber-van Bosse in B⊘rgesen and Cruoria cruoriaeformis (P. et H. Crouan) Denizot are reported. For each species, information on some aspects of their ecology, geographical distribution and notes on their vegetative and reproductive morphology are given.

Organic aggregates formed by benthopleustophyte brown alga Acinetospora crinita (Acinetosporaceae, Ectocarpales)

This work presents the elemental, polysaccharide, and fatty acid compositions of benthic aggregates formed by the filamentous brown alga Acinetospora crinita, which are widely spread on the rocky bottoms of the Mediterranean Sea. The aggregates can be characterized as mineralized centers in which regeneration of nutrients and recycling of dissolved organic matter actively occur and favor the development of an abundant phytoplankton community. Analyses of the stable isotopes of C and N display their marine origin and could provide evidence of the processes that occur inside/outside of the aggregates. The monosaccharide compositions of Adriatic and Tyrrhenian mucilages produced by brown alga A. crinita were quite similar. In particular, the Adriatic sample compositions resembled the average composition of the Tyrrhenian high molecular weight exopolymers, and the observed differences could be ascribed to different degradation stages. The fatty acid patterns found for the aggregates were similar to those observed in the isolated A. crinita algae with variable contributions from embedded diatom species. The bacterial contribution to the fatty acid pool was quite low, most likely due to the known poor conditions for their heterotrophic growth.