Ostreopsis cf. ovata in the Gulf of Gabès (south-eastern Mediterranean Sea): morphological,molecular and ecological characterization

In the last few decades, the frequency of the toxic benthic dinoflagellate Ostreopsis cf. ovata proliferation has increased in the Mediterranean Sea. These blooms are associated with harmful effects on human health and the environment. The present work provides the first long term study on the spatio-temporal distribution of O. cf. ovata in relation to physical parameters in the Gulf of Gabès coastal waters (south-eastern Mediterranean Sea), as well as its morphological, molecular and physiological features. The strains of O. cf. ovata were identified morphologically by light and epifluorescence microscopy. The morphology and the size range of cultured strains were similar to those described regarding O. cf. ovata isolated from the Mediterranean Sea. The ultrastructural analysis of O. cf. ovata cells using the transmission electron microscopy showed the presence of numerous vesicles (VE) containing spirally coiled fibers (SCFs) connected to the mucus canal (CH). The phylogenetic tree based on the internal transcribed spacer region containing the 5.8S rDNA (ITS-5.8S rDNA) revealed that O. cf. ovata strains were placed into the Mediterranean/Atlantic clade. In addition, O. cf. ovata toxicity was evaluated by the mouse bioassay and a dose level ≥ 4 × 10⁴ cells was found to be lethal to mice. The examination of the O. cf. ovata occurrence in the Gulf of Gabès at a large temporal scale (1997–2012) revealed a clear seasonal pattern with dominance from midsummer (July) to late autumn (November). Furthermore, a positive correlation was found between the abundance of O. cf. ovata and salinity, whereas no correlation was found as regards temperature. The occurrence of O. cf. ovata was only detected at salinity above 35 and the highest concentrations were observed at 45. Laboratory experiments confirmed such a result and showed that isolated O. cf. ovata strains had optimal growth at salinity ranging between 35 and 45, with its peak at 40.     

New data on the Devonian and Carboniferous Graptolithina (Dendroidea) from Belgium with notes on possible occurrences of Rhabdopleuridae in the Belgian Carboniferous

An old find of a graptolite from the Eifelian Jemelle Formation, combined with the recent discovery of an exceptionally well-preserved specimen from the Upper Frasnian (Matagne Formation), allow documentation of the geologically oldest and youngest dendroid fossils from the Devonian of Belgium. Both are ascribed to the long-ranging genus Callograptus (Acanthograptidae). These records enlarge the sparse knowledge of graptolite diversity and occurrences along the southern margin of Laurussia during the mid-Paleozoic. In Belgium, Devonian dendroids are exclusively known from the Dinant Synclinorium. The Devonian dendroid faunas previously reported from the Eifelian, Givetian and Frasnian of the Ardenne–Rhenish massifs (Belgium and Germany) are of low diversity (one to five species per locality). The specimens, generally inedaquatelly preserved, were ascribed to the genera Callograptus, Dictyonema, Palaeodictyota?, and Ruedemannograptus? In these massifs, Carboniferous dendroids are only known from the Viséan (Moliniacian) Denée Konservat-Lagerstätte. Other but undocumented reports of dendroids (and rhabdopleurids) are from the historical type area of the Tournaisian Stage (Tournai area, Brabant Parautochthon). Rhabdopleuridae from the Viséan–Serpukhovian of the Campine Basin (Turnhout borehole) remain incompletely known in the absence of the previously described material.     

New remains of Hyaenodontidae (Creodonta,Mammalia) from the Oligocene of Central Mongolia

New specimens of hyaenodontid creodonts are described which were unearthed in Mongolia by the Austrian–Mongolian Paleontological expeditions. Five taxa are identified: Hyaenodon eminus, Hyaenodon pervagus, Hyaenodon cf. incertus, Hyaenodon cf. mongoliensis, and cf. Hyaenodon gigas. Hitherto unknown morphological details are reported for most of these species. The implications to systematic of the species and the genus Hyaenodon are discussed. These Hyaenodon remains suggest a separate evolutionary lineage, with different species in Europe and Asia, even if the genus is also known from contemporary faunas of Europe and North America.     

Les grands mammifères du Villafranchien supérieur des travertins du Bassin de Denizli (Sud-Ouest Anatolie,Turquie)

The large mammals from travertine deposits in the Denizli basin include the following species: Archidiskodon meridionalis meridionalis, Equus cf. altidens s. l., E. cf. apolloniensis, Stephanorhinus cf. etruscus, Metacervoceros rhenanus, Cervalces (Libralces) ex gr. minor-gallicus, Palaeotragus sp., Bovinae gen. and sp. indet. This association resembles those from the late Villafranchian of Southern and Eastern Europe, and, to some extent, fromWestern Asia, and could be older than 1.2 Ma.     

Re-interpreting the biochronology of the La Celia and Los Gargantones mammal sites (Late Miocene,Murcia, Spain)

The biochronological age of the small-mammal populations of Los Gargantones 1, 2 and La Celia (upper Miocene, La Celia sub-basin, Murcia, Spain) is re-interpreted. The presence in Los Gargantones of Occitanomys adroveri, Parapodemus barbarae, Parapodemus cf. gaudryi, Huerzelerimys turoliensis, Atlantoxerus cf. adroveri, and Alilepus evidences a correlation to MN12 (∼7.5–7 Ma) rather than to MN11 (∼9–7.5 Ma), as inferred previously. The assemblage corresponds to that of the more eastern, near-coast sites of Crevillente 8 and 15, situated in the Alicante area. The stratigraphically highest site of La Celia contains Hispanomys adroveri, a species also indicative of MN12. The presence of Castromys cf. littoralis together with an advanced O. adroveri points to a slightly younger age than that of Los Gargantones, approaching that of MN13 sites. The assemblage best matches that of Crevillente 17. Other species described in this paper are Prolagus crusafonti, Prolagus sp., Parasorex cf. ibericus, Panelimnoecus cf. repenningi, and Blarinella aut Petenyia sp. indet.     

Distribution and molecular phylogeny of the dinoflagellate genus Ostreopsis in Thailand

The toxic benthic dinoflagellate genus Ostreopsis has been connected to the production of palytoxin and its analogs in many tropical and temperate areas. Although the type species, O. siamensis, was originally described from the Gulf of Thailand in 1901, little is known about the species composition and distribution of the genus Ostreopsis in Thailand. In this study, a total of 64 Ostreopsis strains isolated from the Andaman Sea as well as the Gulf of Thailand were investigated by analyzing the nucleotide sequences of the LSU rDNA D1/D2, D8/D10 and ITS-5.8S rDNA regions. Phylogenetic analyses (BI and ML) resulted in some of the strains being assigned to previously described clades, O. cf. ovata and Ostreopsis sp. 6, and revealed the existence of a novel clade named Ostreopsis sp. 7, which exhibited large genetic distances from the other clades. Among O. cf. ovata, several strains from Thailand were formed into a new subclade, the Thailand subclade, whereas a few strains belonged to the South China Sea subclade. Morphometric characteristics such as the cell sizes of the two O. cf. ovata subclades and those of Ostreopsis sp. 7 were not significantly different from each other (p > 0.05). Their characteristics were similar but slightly different from those of O. ovata and were significantly different from those of Ostreopsis sp. 6 (p < 0.05). Toxicities of Ostreopsis from Thailand were evaluated using mouse bioassay. Strains of Ostreopsis sp. 6 and Ostreopsis sp. 7 tested were highly toxic, while the two subclades of O. cf. ovata strains seemed to be nontoxic. This study suggests that toxic Ostreopsis sp. 7 is distributed in the Andaman Sea, whereas the two subclades of O. cf. ovata and toxic Ostreopsis sp. 6 are distributed in the Gulf of Thailand.     

The mammal fauna from the late Early Biharian site of Castagnone (Northern Monferrato, Piedmont, NW Italy)

Small and large mammals associated in Early Pleistocene floodplain sediments outcropping near Castagnone (Cerrina Valley, northern Monferrato Hills, Piedmont, NW Italy) are here examined, with particular emphasis on the voles. The micromammal assemblage includes Talpa sp., Sciurus cf. S. warthae, Mimomys savini, Mimomys pusillus, Microtus (Allophaiomys) cf. M. (A.) nutiensis, Ungaromys cf. U. nanus, Apodemus mystacinus, Leporidaeindert. and the associated macrofauna lists the following generic Galerian components: Stephanorhinus cf. S. hundsheimensis, Sus sp., Hippopotamus sp., Capreolus sp. and other Cervidae indet. (a fallow-deer and a megacerine), Bison sp. and Elephantidae indet. Due to the co-occurrence of U. nanus and an evolutionary advanced form of Allophaiomys with the normal paleomagnetic polarity of the embedding sediments, this faunal assemblage can be biochronologically dated to the late Early Biharian within the Jaramillo subchron.     

Correlation ofHipparion faunal components in the East mediterranean and paratethys areas

Several species ofHipparion from Turolian/Middle Sarmatian-Meotian faunas in the East Mediterranean and Paratethys areas are compared. The large hipparions common to the faunas are referred toH. primigenium (v. Meyer), the smaller hipparions discussed belong to the speciesH. verae Gabunia,H. mediterraneum Roth & Wagner,H. cf.moldavicum Gromova, andH.schlosseri Antonius. A correlation of the faunas in the two areas is attempted on the basis of evolutionary events (e. g. radiation) and the presence of taxonomically similar species.     

Geographic variation in the skulls of the horseshoe bats,Rhinolophus simulator and R. cf. simulator: Determining the relative contributions of adaptation and drift using geometric morphometrics

The relative contributions of adaptation and genetic drift to morphological diversification of the skulls of echolocating mammals were investigated using two horseshoe bat species, Rhinolophus simulator and R. cf. simulator, as test cases. We used 3D geometric morphometrics to compare the shapes of skulls of the two lineages collected at various localities in southern Africa. Size and shape variation was predominantly attributed to selective forces; the between‐population variance (B) was not proportional to the within‐population variance (W). Modularity was evident in the crania of R. simulator but absent in the crania of R. cf. simulator and the mandibles of both species. The skulls of the two lineages thus appeared to be under different selection pressures, despite the overlap in their distributions. Difference in the crania of R. cf. simulator was centered largely on the nasal dome region of R. cf. simulator but on the cranium and mandibles of R. simulator. It is likely that the size and shape of the nasal dome, which acts as a frequency‐dependent acoustic horn, is more crucial in R. cf. simulator than in R. simulator because of the higher echolocation frequencies used by R. cf. simulator. A larger nasal dome in R. cf. simulator would allow the emission of higher intensity pulses, resulting in comparable detection distances to that of R. simulator. In contrast, selection pressure is probably more pronounced on the mandibles and cranium of R. simulator to compensate for the loss in bite force because of its elongated rostrum. The predominance of selection probably reflects the stringent association between environment and the optimal functioning of phenotypic characters associated with echolocation and feeding in bats.     

A first report of Prolinograptus packhami Rickards and Wright, 1997 from Baltica,Poland

A well-preserved isolated graptolite Prolinograptus packhami Rickards and Wright, 1997, well known from Australia, is described for the first time in Europe. The genus has now been recognized in three continents (Australia, Europe and North America). The Australian P. packhami occurs in the Neocucullograptus inexpectatus/Neocucullograptus kozlowskii biozonal interval, while the form from the Mielnik IG-1 core, Poland, appears earlier, in the Bohemograptus praecornutus Biozone. Prolinograptus, of unclear origin, is one of the least-known genera of the subfamily Linograptinae. P. packhami, along with Neodiversograptus palmeri and Prolinograptus orangensis, form a group of very diminutive specimens, with slender stipes and thecal apertures showing varying degrees of eversion. Scanning electron microscope examination revealed the presence of some micro-ornamentation on the rhabdosome surface of the Polish Prolinograptus, similar to that known in retiolitids (Retiolitidae).     

Cryptic diversity,pathogenicity, and evolutionary species boundaries in Cercospora populations associated with Cercospora leaf spot of Beta vulgaris

The taxonomy and evolutionary species boundaries in a global collection of Cercospora isolates from Beta vulgaris was investigated based on sequences of six loci. Species boundaries were assessed using concatenated multi-locus phylogenies, Generalized Mixed Yule Coalescent (GMYC), Poisson Tree Processes (PTP), and Bayes factor delimitation (BFD) framework. Cercospora beticola was confirmed as the primary cause of Cercospora leaf spot (CLS) on B. vulgaris. Cercospora apii, C. cf. flagellaris, Cercospora sp. G, and C. zebrina were also identified in association with CLS on B. vulgaris. Cercospora apii and C. cf. flagellaris were pathogenic to table beet but Cercospora sp. G and C. zebrina did not cause disease. Genealogical concordance phylogenetic species recognition, GMYC and PTP methods failed to differentiate C. apii and C. beticola as separate species. On the other hand, multi-species coalescent analysis based on BFD supported separation of C. apii and C. beticola into distinct species; and provided evidence of evolutionary independent lineages within C. beticola. Extensive intra- and intergenic recombination, incomplete lineage sorting and dominance of clonal reproduction complicate evolutionary species recognition in the genus Cercospora. The results warrant morphological and phylogenetic studies to disentangle cryptic speciation within C. beticola.     

Systematics,palaeoecology and palaeobiogeography of the Neogene fossil sharks from the Azores (Northeast Atlantic)

The Azores Archipelago is a group of isolated islands located in the North Atlantic Ocean. One of these oceanic islands – Santa Maria – exhibits marine fossiliferous sediments of late Miocene/early Pliocene and also of Pleistocene age. Recent research provided new selachian fossil material, with three new records (Carcharias acutissima, Megaselachus megalodon, and Carcharhinus cf. leucas) increasing the number of fossil sharks reported from the Azores (Santa Maria Island) to seven species (Notorynchus primigenius, C. acutissima, Cosmopolitodus hastalis, Paratodus benedenii, Isurus oxyrinchus, M. megalodon, and C. cf. leucas). So far, no teeth of batoids or small sharks have been found despite the screen-washing of several sediment samples from Santa Maria. The Azorean Mio-Pliocene selachian fauna clearly differs from those described from sediments deposited on continental shelves, in which batoids and small benthic sharks (e.g., scyliorhinids) are usually well represented. During the late Miocene/early Pliocene, subtropical to warm-temperate seas were prevalent in the area of the Azores, as deduced from palaeontological, geological and isotopic data, all indicating a warmer climate than in the present.     

A THEORETICAL CONSIDERATION OF THE ACTION OF X-RAYS ON THE PROTOZOAN COLPIDIUM COLPODA

1. The theory which Crowther has advanced to account for the variation of the lethal dose of roentgen rays among the individuals of a group of Colpidium colpoda is reviewed. 2. It is shown that the use of his small-body theory to explain the small value of λ_e leads to certain further assumptions about the nature of the destructive effect. 3. An alternative hypothesis is discussed.     

Nucleotide sequence and evolution of a mammalian α-Tubulin messenger RNA

Bacterial clones containing complementary DNA sequences specific for rat brain α-tubulin messenger RNA were constructed. One plasmid, pILαTl, contains >95% of the sequences found in the mRNA: the entire coding sequence as well as extensive 5′ and 3′ untranslated sequences. Comparison of the rat amino acid sequence with the known chicken α-tubulin sequence (Valenzuela et al., 1981) reveals the extraordinary evolutionary stability of α-tubulin protein. The presence of only two interspecies amino acid differences within analogous 411 amino acid sequences predicts that amino acid substitutions in this protein are fixed with a unit evolutionary period (Wilson et al., 1977) of 550 million years (i.e. the time required for a 1% difference to arise within a specific protein in two diverging evolutionary lineages). An analysis of the silent nucleotide differences, permissible because of the degeneracy of the genetic code, demonstrates that these might not occur in a random fashion. The high guanine-cytosine bias in silent codon positions within the chicken α-tubulin sequence, previously noted by Valenzuela et al. (1981), is not conserved within the rat sequence. This decrease in guanine-cytosine bias is accompanied by a selective loss of CpG dinucleotides in the rat sequence.     

Tragoportax cf. rugosifrons (Schlosser, 1904) from the late Miocene of Cessaniti (Southern Italy)

This paper describes remains attributable to Tragoportax cf. rugosifrons (Schlosser, 1904) found in the late Miocene site of Cessaniti (Vibo Valentia, Calabria) and the surrounding area. The studied specimens come from the Clypeaster sandstones, included in a marine/fluvial succession dated between 8 and 7.2 Ma. At Cessaniti, Tragoportax is associated with Stegotetrabelodon syrticus Petrocchi, 1941; Samotherium cf. boissieri Forsyth-Major, 1888; Bohlinia cf. attica Matthew, 1929; and an undetermined Rhinocerotid still under study. The genus Tragoportax was common in Eurasia and Africa during the late Miocene. The occurrence of Tragoportax cf. rugosifrons at Cessaniti confirms the peculiarity of the assemblage, with its association of species of North African and Pikermian (Greco-Iranian bioprovince) affinities.     

First record of Devonian orthoceratid-bearing limestones in southern Calabria (Italy)

Lower to Middle Devonian orthoceratid-bearing nodular limestones in Calabria are described here for the first time, along the Fiumara Assi section. The succession is tectonically inverted and has been dated by conodonts. The lower beds are Lochkovian–Lower Pragian, because they provided Icriodus cf. steinachensis and Pelekysgnathus serratus, which occur in the delta-sulcatus Zones. Upwards appear Polygnathus cf. dehiscens, corresponding to the dehiscens-gronbergi Zones, and Ozarkodina cf. steinhornensis miae of the dehiscens-inversus Zones, both indicating a topmost Pragian–Lower Emsian age. The Eifelian (or younger) age for the top of the succession is demonstrated by Polygnathus linguiformis linguiformis. This succession, as well as similar coeval deposits of the southern Variscan Chain (southwestern Sardinia, eastern Pyrenees), Betic–Rifian Maláguides-Ghomarides and southern Alps, made part of a western embayment of the Palaeotethys.     

Ecophysiological capability ofMarenzelleria populations inhabiting North Sea estuaries: an overview

The metabolic responses ofMarenzelleria cf.wireni, a newly established polychaete worm within North Sea estuaries, to various kinds of environmental stress are summarised. With respect to salinity,M. cf.wireni is able to deal with variations within a wide range. In the process of osmotic acclimation, free amino acids are involved. The major amino acid in terms of osmotic effector is glycine, followed by alanine. Under severe hypoxia,M. cf.wireni switches to an anaerobic metabolism, but at a very low oxygen partial pressure (<3 kPa), which indicates efficient utilisation of oxygen. Anaerobic energy production occurs predominantly via the succinate-propionate pathway. When exposed to hydrogen sulphide,M. cf.wireni is able to cope with high sulphide concentrations (up to 3 mmol l^?1), but the pattern of end products of the anaerobic energy metabolism changes. In terms of sulphide tolerance,M. cf.wireni probably is even better adapted than other, indigenous polychaetes. However, in comparison with the sibling speciesMarenzelleria viridis, which appeared at the same time in European waters but mainly inhabits the coastal inlets of the Baltic Sea in high numbers, the metabolic capabilities ofM. cf.wireni seem to be more limited at higher sulphide concentrations (>1 mmol l^?1). This might have an influence on the distribution pattern of the two sibling species.     

CF45-1, a secreted protein which participates in Dictyostelium group size regulation

Developing Dictyostelium cells aggregate to form fruiting bodies containing typically 2 × 10⁴ cells. To prevent the formation of an excessively large fruiting body, streams of aggregating cells break up into groups if there are too many cells. The breakup is regulated by a secreted complex of polypeptides called counting factor (CF). Countin and CF50 are two of the components of CF. Disrupting the expression of either of these proteins results in cells secreting very little detectable CF activity, and as a result, aggregation streams remain intact and form large fruiting bodies, which invariably collapse. We find that disrupting the gene encoding a third protein present in crude CF, CF45-1, also results in the formation of large groups when cells are grown with bacteria on agar plates and then starve. However, unlike countin⁻ and cf50⁻ cells, cf45-1⁻ cells sometimes form smaller groups than wild-type cells when the cells are starved on filter pads. The predicted amino acid sequence of CF45-1 has some similarity to that of lysozyme, but recombinant CF45-1 has no detectable lysozyme activity. In the exudates from starved cells, CF45-1 is present in a ~450-kDa fraction that also contains countin and CF50, suggesting that it is part of a complex. Recombinant CF45-1 decreases group size in colonies of cf45-1⁻ cells with a 50% effective concentration (EC₅₀) of ~8 ng/ml and in colonies of wild-type and cf50⁻ cells with an EC₅₀ of ~40 ng/ml. Like countin⁻ and cf50⁻ cells, cf45-1⁻ cells have high levels of cytosolic glucose, high cell-cell adhesion, and low cell motility. Together, the data suggest that CF45-1 participates in group size regulation in Dictyostelium.