Analysis of genetic structure of the red shrimp <Emphasis Type="Italic">Aristeus antennatus</Emphasis> from the Western Mediterranean employing two mitochondrial regions

In this paper we addressed the phylogeographical genetic structure of the economically important red shrimp, Aristeus antennatus (Crustacea, Aristeidae) in the Western Mediterranean. Partial mitochondrial regions of the cytochrome c oxidase subunit I (514 bp) and ribosomal 16S subunit (547 bp) were sequenced in 137 individuals collected at three localities: Catalan Sea, Ligurian Sea and the southern Tyrrhenian Sea. Values of haplotypic diversity were h = 0.552–0.724, whereas those for nucleotide diversity were π = 0.0012–0.0026. Among-sample genetic diversity was not significant and no geographical patterns in the distribution of haplotypes were apparent. Results of the present study are consistent with a past population expansion that occurred <2,000 years ago. Despite the current fishing pressure, genetic variability appears to be sufficiently high to keep A. antennatus populations stable over time. Dispersal-related life history traits may account for the shallow genetic structure. Our results are not in contrast with the hypothesis of sustainability of Western Mediterranean red shrimp fisheries predicted on the basis of previously obtained biological results.     

A comparative study on recurrent blooms of Alexandrium minutum in two Mediterranean coastal areas

Alexandrium minutum is a toxic dinoflagellate widespread along the Mediterranean coasts. This species is frequently detected year-round at low concentrations within the Mediterranean basin. However, it only proliferates recurrently in some localities. Two affected areas are the Catalan and Sicilian coasts. In order to identify the factors determining the A. minutum blooms in the Mediterranean Sea, we compare the bloom conditions in two harbours: Arenys de Mar (Catalan coast, Spain) and Syracuse (Sicily, Italy), during 2002–2003. Arenys de Mar harbour is a fishing and leisure harbour and receives an input of freshwater rich in nutrients. Likewise, the Syracuse harbour – located on the Ionian coast of Sicily – is subject to freshwater inputs. Some points of this site are used for productive activities such as shellfish farming. A. minutum from the two areas studied were morphologically and genetically identical. In both sites, recurrent blooms take place from winter to spring. Surface water temperatures and salinities during A. minutum bloom events were 12–14.5 °C and 32–38, and 16–24 °C and 32–37.7 for Arenys and Syracuse, respectively. During the blooms, the spatial distribution of A. minutum in the two harbours, the physicochemical characteristics and the phytoplankton community were studied. Similarities in composition of the phytoplankton community were evidenced, with a clear dominance of dinoflagellates over the other taxa. In Arenys, the second dominant species was Prorocentrum micans followed by Scrippsiella spp. and Dinophysis sacculus. The same species were found in Syracuse although P. triestinum, and alternatively Lingulodinium polyedrum, reached cell densities much higher than the other dinoflagellates giving marked water discolourations.     

Stimulation of sulfate reduction rates in Mediterranean fish farm sediments inhabited by the seagrass <Emphasis Type="Italic">Posidonia oceanica</Emphasis>

Sulfate reduction rates and biogeochemical parameters of fish farm sediments across the Mediterranean were investigated in the order to evaluate the potential effects of organic matter inputs on habitat quality for the common seagrass Posidonia oceanica. Four study sites were selected in Spain, Italy, Greece and Cyprus to represent the Mediterranean basin. P. oceanica was found in immediate vicinity of all the farms, which were located at physically exposed sites about 1 km from the shore lines. Organic matter accumulation, sulfate reduction rates and sulfur pools were measured in depth profiles along transects from the farms in both bare and vegetated sediments. Results show that although the organic matter accumulation was minor at the sites (POC < 2.8% DW), the sulfate reduction rates were high, in particular at the largest farm in Italy (up to 212 mmol m⁻² d⁻¹), similar to rates found at shallower, temperate fish farm sites, where higher sedimentation rates can be expected. Sulfate reducing bacteria in these low-organic, carbonate-rich Mediterranean sediments respond strongly to organic matter loadings and cause habitat degradation. Sulfate reduction rates measured in the P. oceanica sediments were among the highest recorded (7.8–42.0 mmol m⁻² d⁻¹) similar to rates found in degrading meadows impacted by organic matter loadings. As sulfate reduction rates were correlated with the sedimentation rates along the transects rather than organic matter pools this suggests mineralization processes were controlled by organic matter loading in fish farm sediments. The vegetated sediments near the net cages were more reduced due to accumulation of sulfides compared to control sites, which is a possible contributing factor to the observed seagrass decline in the farm surroundings. It is recommended that Mediterranean fish farms are placed in areas with rapid dispersal of particulate waste products to minimize organic matter loading of the sediments and thereby preserve habitat quality for benthic fauna and flora.     

New species in the genus <Emphasis Type="Italic">Francisella</Emphasis> (Gammaproteobacteria; Francisellaceae); <Emphasis Type="Italic">Francisella piscicida</Emphasis> sp. nov. isolated from cod (<Emphasis Type="Italic">Gadus morhua</Emphasis>)

A Francisella strain, GM2212, previously isolated from moribund farmed Atlantic cod (Gadus morhua) in Norway, is closely related to Francisella philomiragia among Francisella spp. according to its complete 16S rDNA, 16S-23S intergenic spacer, 23S rDNA, 23S–5S intergenic spacer, 5S rDNA, FopA, lipoprotein TUL4 (LpnA), malate dehydrogenase and hypothetical lipoprotein (LpnB) sequences. A comparison between GM2212 and the type strain of Francisella philomiragia were performed by DNA–DNA hybridization and fatty acid analysis. The DNA–DNA hybridization showed a 70% similarity. The fatty acid analysis showed only minor differences between the Francisella isolates. Due to the inconclusive result from the DNA–DNA hybridisation, major emphasis concerning the status of this isolate is made on previously published molecular, phenotypic and biochemical characters. All characteristics taken together support the establishment of GM2212 as a novel species, for which the name Francisella piscicida sp. nov. is proposed (=CNCM I-3511^T = DSM 18777^T = LMG registration number not yet available).     

Time-Series Evolution of Toxic Organisms and Related Environmental Factors in a Brackish Ecosystem of the Mediterranean Sea

In the framework of the EU Project STRATEGY, a short-term study was carried out in the Marinello ecosystem, a small brackish area located on the Tyrrhenian coast of Sicily (Italy). The investigation was aimed at understanding the dynamics of phytoplankton toxic blooms in relation to other planktonic species and environmental conditions. The study started on 10 March 2003, in coincidence with the first detection of Alexandrium minutum, a dinoflagellate known as a producer of Paralyzing Shellfish Toxins (PST) and lasted until 4 June 2003, when the bloom collapsed. The specific identity of A. minutum was confirmed on field mixed samples, through the use of species-specific PCR-primers targeting the 5.8S rDNA-ITS regions. Water samples and phytoplankton net hauls were taken approximately at 10 days intervals in the Verde Pond, one of the five basins of the Marinello ecosystem, in order to evaluate the incidence of toxic and non-toxic dinoflagellate species over the whole planktonic community. The evolution of the main environmental and trophic parameters (temperature, salinity, dissolved oxygen, POC, C/N, DIN, PO₄–P) was simultaneously investigated. Alexandrium blooms were mostly characterized by A. minutum (max. 6 × 10⁵ cells l⁻¹ on April 11) and Alexandrium tamarense as an associated species (max. 2.5 × 10⁴ cells l⁻¹ on March 25). During the bloom, dinoflagellates or small flagellates dominated over the other taxa, with a minimum incidence of diatoms. The load of dissolved inorganic nitrogen was maximum in the pre-bloom phase (29 μM on March 19), after which it decreased sharply. An oxygen supersaturation event was registered in coincidence with the A. minutum bloom. The amounts of POC ranged between 266 and 658 μg l⁻¹ showing a discontinuous temporal trend. A recent introduction of A. minutum into the Verde Pond is suggested on the basis of the absence of this species in past years.     

Trawl Selectivity Trials on the Deep-water Rose Shrimp (Parapenaeus longirostris) in Sicilian Waters

The selectivity of the traditional commercial bottom trawl net employed in Sicily to catch the Mediterranean deep-water rose shrimp, Parapenaeus longirostris, has been assessed. Two fishing campaigns were carried out in the Strait of Sicily and in the Southern Tyrrhenian Sea, using the covered cod-end method (mesh 20 mm vs. 31 mm). Of a total catch of 11,601 individuals, 23.4% escaped in the cover; the sample length structure from the Strait is unimodal, while that from the Tyrrhenian, polymodal. A logistic curve, fitted with a maximum likelihood criterion, has been used to model the selectivity data, in order to obtain the parameters CL_c50% (50% retention size), SR_75–25% (selection range) and SF (selection factor, i.e. CL_c50%/mesh). The two sets of data, besides a larger selection range for the Strait sample (5.2 mm vs. 2.3 mm), produced very similar estimates (retention sizes of 13.0 mm vs. 12.8 mm CL), fitting the logistic curve well. Almost no shrimp larger than 20 mm does escape from the cod-end; moreover, from the amount of damaged specimens found in the cover, even the evaded shrimps sustain a high fishing mortality. An increase of the present cod-end mesh opening, even above the size required by the EU bylaws (at present, 40 mm stretched) seems necessary for managing the fishery.     

Comparative Tolerances of Various <Emphasis Type="Italic">Beauveria bassiana</Emphasis> Isolates to UV-B Irradiation with a Description of a Modeling Method to Assess Lethal Dose

The tolerances of 20 Beauveria bassiana isolates derived from host insects worldwide to UV-B irradiation were assessed quantitatively in multi-dose bioassays. Conidial suspensions of the isolates smeared on glass slides were exposed to the gradient UV-B doses of 0.1–1.6 J cm⁻² (D), which generated from 0.75 to 10.17 min irradiation of weighted 312-nm wavelength at 2.0–2.61 mW cm⁻². Irradiated conidia were then incubated for 24 h at 25°C under saturated humidity. The ratio of germination at each dose over that in the blank control was defined as survival index (I _s). For all isolates, the I _s − D observations fit well with the survival model I _s = 1/[1 + exp(a + bD)] (0.94 ≤ r ² ≤ 0.99) generated widely spanned lethal doses of 0.154–0.928, 0.240–1.139, and 0.383–1.493 J cm⁻² for their losses of 50%, 75%, and 95% viabilities, respectively. These were far below the solar UV-B dose of 2.439 J cm⁻² measured in a sunny day during the summer. The large variation of UV-B tolerance among the isolates indicates a necessity to select UV-tolerant candidates for formulations applied to insect control during summer. The highly efficient bioassay method was developed to measure accurately the UV-B tolerances of fungal biocontrol agents as lethal doses.     

First detection of <Emphasis Type="Italic">Rickettsia slovaca</Emphasis> in Greece

Seven hundred and three ticks collected in November and June of 2004–2006 from domestic animals in four localities of Halkidiki prefecture, Northern Greece, were tested for the presence of ricketsial DNA. Rickettsia slovaca was detected in one pool of Rhipicephalus bursa ticks, representing the first report of detection of R. slovaca in Greece.     

Syntaxonomy and Synecology of <Emphasis Type="Italic">Quercus coccifera</Emphasis> Mediterranean Shrublands in Greece

Quercus coccifera (kermes oak) is the most common species of the Mediterranean maquis with a wide distribution across the Mediterranean Basin. This paper presents a syntaxonomic overview of the Q. coccifera plant communities in the Mediterranean zone of Greece (Quercetea ilicis) based on the classification of 221 relevés from 34 (17 continental and 17 insular) mountainous areas throughout Greece. Two associations and eight sub-associations are described and presented in a synoptic constancy table. Querco cocciferae–Pistacietum lentisci is the most widespread, is found in the entire continental Greece and most islands, and is further subdivided into five sub-associations reflecting primarily local peculiarities in the disturbance regime and the influence of local floristic elements. Rhamno lycioidis–Cocciferetum (Rivas Goday & Rivas-Martínez 1954), on the other hand, is geographically confined on the island of Crete and is further subdivided into three sub-associations, reflecting differences in the annual precipitation, and they are characterized by the presence of many phryganic and grazing-resistant species. Climate and the anthropogenic pressure have been identified to be the most important factors determining the structure and the floristic composition of Q. coccifera Mediterranean shrublands of Greece.     

Cereulide-producing strains of <Emphasis Type="Italic">Bacillus cereus</Emphasis> show diversity

Producers of cereulide, the emetic toxin of Bacillus cereus, are known to constitute a specific subset within this species. We investigated physiological and genetic properties of 24 strains of B. cereus including two high cereulide producers (600–1,800 ng cereulide mg⁻¹ wet weight biomass), seven average producers (180–600 ng cereulide mg⁻¹ wet weight biomass), four low cereulide producers (20–160 ng cereulide mg⁻¹ wet weight biomass) and 11 non-producers representing isolates from food, food poisoning, human gut and environment. The 13 cereulide producers possessed 16S rRNA gene sequences identical to each other and identical to that of B. anthracis strains Ames, Sterne from GenBank and strain NC 08234–02, but showed diversity in the adk gene (two sequence types), in ribopatterns obtained with EcoRI and PvuII (three types of patterns), in tyrosin decomposition, haemolysis and lecithin hydrolysis (two phenotypes). The cereulide-producing isolates from the human gut represented two ribopatterns of which one was novel to cereulide-producing B. cereus and two phenotypes. We conclude that the cereulide-producing B. cereus are genetically and biochemically more diverse than hitherto thought.     

Fumigant toxicity of cassia bark and cassia and cinnamon oil compounds to <Emphasis Type="Italic">Dermatophagoides </Emphasis><Emphasis Type="Italic">farinae </Emphasis>and <Emphasis Type="Italic">Dermatophagoides pteronyssinus</Emphasis> (Acari: Pyroglyphidae)

The toxicity to adults of the American house dust mite, Dermatophagoides farinae, and the European house dust mite, Dermatophagoides pteronyssinus, of cassia bark and cassia and cinnamon oil compounds was examined using residual contact and vapour-phase toxicity bioassays. Results were compared with those of the currently used acaricides: benzyl benzoate and dibutyl phthalate. The acaricidal principles of cassia bark were identified as (E)-cinnamaldehyde and salicylaldehyde. In fabric-circle residual contact bioassays with adult D. farinae, salicylaldehyde (17.3 mg/m²) and (E)-cinnamaldehyde (25.8 mg/m²) were 2.5 and 1.7 times more toxic than benzyl benzoate (43.7 mg/m²), respectively, based on 24-h LD₅₀ values. The acaricidal activity was more pronounced in benzaldehyde, menthol, α-terpineol, and thymol (70.8–234.3 mg/m²) than in dibutyl phthalate (281.0 mg/m²). Against adult D. pteronyssinus, salicylaldehyde (17.3 mg/m²) and (E)-cinnamaldehyde (19.3 mg/m²) were 2.4- and 2.2-fold more active than benzyl benzoate (41.9 mg/m²). The toxicity of benzaldehyde, menthol, α-terpineol, and thymol (75.3–179.2 mg/m²) was higher than that of dibutyl phthalate (285.1 mg/m²). In vapour-phase toxicity tests with adult D. farinae, the test compounds described were much more effective in closed—but not in open—containers, indicating that the effect of these compounds was largely a result of action in the vapour phase.     

The effect of biochanin A on the chlorophylls and carotenoids content in the alga <Emphasis Type="Italic">Chlorella vulgaris</Emphasis> Beijerinck

The present study was undertaken to determine the influence of biochanin A, isoflavone characterised by estrogenic activity, upon the content of chlorophylls and carotenoids in the cells of green alga Chlorella vulgaris Beijerinck (Chlorophyceae). On the 6^th day of cultivation under the influence of 10⁻⁶ M biochanin A exerted the greatest biological activity and the most stimulating effect on the analysed parameters: growth of the alga expressed by the cells number and the content of photosynthetic pigments in them. The total content of carotenoids was stimulated on the 6^th day of experiment in the range of 197 % but during the 9^th day only in 179 % in comparision with the control group (100 %). At the same time content of carotenes increased to the level of 123 – 119 % and xanthophylls to 208 – 178 %. Among the carotenes, β-carotene was characterised with the 3.7 times higher content in regard to the content of α-carotene on the 6^th day of cultivation and during the 9^th day — the 5.7 times domination. The content of xanthophylls that contain two atoms of oxygene in molecule (oxygen — poor xanthophylls) was intensively stimulated in the range of 224 %. Moreover, the oxygen — rich xanthophylls content reached the value 179 % when compared to the control. The greatest stimulation of the content of chlorophylls and its isomers was observed during the 3^rd day of cultivation of Chlorella vulgaris when it rose up to 166 % and to 156 % on the 6^th day. The content of chlorophyll b and its isomers was stimulated in 181 % on the 6^th day of culture and 155 % during the 9^th day of algal culture. The evidence on the stimulating effect of biochanin A as the main representative of isoflavones on the growth and content photosynthetic pigments in eucaryotic alga C. vulgaris was demonstrated in these studies.     

An unusual cyanobacterium from saline thermal waters with relatives from unexpected habitats

Cyanobacteria that grow above seawater salinity at temperatures above 45°C have rarely been studied. Cyanobacteria of this type of thermo-halophilic extremophile were isolated from siliceous crusts at 40–45°C in a geothermal seawater lagoon in southwest Iceland. Iceland Clone 2e, a Leptolyngbya morphotype, was selected for further study. This culture grew only at 45–50°C, in medium ranging from 28 to 94 g L⁻¹ TDS, It showed 3 doublings 24 h⁻¹ under continuous illumination. This rate at 54°C was somewhat reduced, and death occurred at 58°C. A comparison of the 16S rDNA sequence with all others in the NCBI database revealed 2 related Leptolyngbya isolates from a Greenland hot spring (13–16 g L⁻¹ TDS). Three other similar sequences were from Leptolyngbya isolates from dry, endolithic habitats in Yellowstone National Park. All 6 formed a phylogenetic clade, suggesting common ancestry. These strains shared many similarities to Iceland Clone 2e with respect to temperature and salinity ranges and optima. Two endolithic Leptolyngbya isolates, grown previously at 23°C in freshwater medium, grew well at 50°C but only in saline medium. This study shows that limited genotypic similarity may reveal some salient phenotypic similarities, even when the related cyanobacteria are from vastly different and remote habitats.     

A halotolerant and thermotolerant <Emphasis Type="Italic">Bacillus</Emphasis> sp. degrades hydrocarbons and produces tensio-active emulsifying agent

A Bacillus sp. strain DHT, isolated from oil-contaminated soil, grew and produced biosurfactant when cultured in variety of substrate at salinities of up to 100 g l⁻¹ and temperatures up to 45°C. It was capable of utilizing crude oil, fuels, various pure alkanes and PAHs as a sole carbon and energy source across a wide range of temperature and salinity. Over the range evaluated, the degradation of hydrocarbon and biosurfactant production was not influenced by salinity (0–10% wv⁻¹) and temperature (30–45°C). The biosurfactant produced by the organism emulsified a range of hydrocarbons with hexadecane as the best substrate and toluene as the poorest. From 16S rDNA analysis, strain DHT was related to Bacillus licheniformis.     

Fish Farming Effects on Chemical and Microbial Variables of the Water Column: A Spatio-temporal Study Along the Mediterranean Sea

The effects of fish farming on chemical and biological variables of the water column were investigated in three coastal locations along the Mediterranean (Spain, Italy and Greece). Analyses of nutrients, chlorophyll a, particulate organic carbon and nitrogen (POC and PON), heterotrophic bacteria and cyanobacteria (Synechococcus) were carried out on integrated samples (0–30 m depth) taken at various distances from fish farms and the respective reference sites. At one of these sites, water samples were collected by means of Niskin bottles at 09:00, 13:00 and 16:00 h and at three different depths (0 m, 10 m and bottom). Integrated sampling showed no significant changes with distance in any of the variables measured, whereas all variables except PON showed significant changes between the three locations studied. However, changes were found in samples taken by Niskin bottles, with increased concentrations of NH₄⁺, POC, PON and decreased cyanobacteria densities at the surface layer in the immediate vicinity of the cages. Samples taken at the cages in the afternoon showed increased PO₄³⁻ concentrations in comparison to those taken in the morning. Dilution and grazing are probably both responsible for the lack of detectable signs of eutrophication.     

Chromium(VI)-reducing <Emphasis Type="Italic">Chlorella</Emphasis> spp. isolated from disposal sites of paper-pulp and electroplating industry

We isolated four cultures of chromate resistant, unicellular, non-motile green algae from disposal sites of the paper-pulp and electroplating industries. These algae were maintained in Tris-acetate-glycerophosphate medium containing 30 μM K₂Cr₂O₇. The morphological features as well as analysis of the 500-bp fragment of 18S rDNA (NS 12 region) showed that these isolates belong to Chlorella spp. These isolates showed EC₅₀ values for chromate ranging from 60 to 125 μM. Uptake studies with radioactive ⁵¹Cr(VI) showed that 10–19% of total radioactivity was intracellular, and 1–2% was bound to the cell wall. The rest of the activity remained in the medium, suggesting that resistance was not related to accumulation of Cr(VI) in the cells. Interestingly, when these isolates were grown in the presence of 30 μM of K₂Cr₂O₇, a decrease in the Cr(VI) concentration in the medium was observed. Only live cells could deplete Cr(VI) from the supernatant, suggesting the presence of chromium reduction activity in these Chlorella isolates. Cr(VI) reduction activity of the cells of Chlorella was stimulated by light as well as by acetate and glycerophosphate. Treatment of Chlorella cells with 3-(3,4 dichlorophenyl),1,1dimethyl urea (DCMU) did not affect the Cr(VI) reduction. However, if the cells were treated with sodium azide, Cr(VI) reduction was severely affected. Though chromate resistance has been well documented in algae, the information on chromate reduction by algae is scant. This paper discusses the Cr(VI) reduction by Cr(VI) resistant Chlorella, which may find a use in the effective bioremediation of Cr(VI).     

<Emphasis Type="Italic">Cyperaceae</Emphasis> and <Emphasis Type="Italic">Juncaceae</Emphasis> pollination measured in the air at two sites in SW Spain

The presence of airborne Cyperaceae and Juncaceae pollen was quantified using volumetric aerobiological traps over a 10-year period at two sites in SW Spain separated by 60 km (Badajoz 10 years, Mérida 3 years). The Pearson correlation coefficient was calculated between the daily and hourly concentrations. The values of the principal meteorological parameters—temperature, rainfall, relative humidity, and speed and direction of the wind—were calculated during the study period, and with the accumulated values corresponding to the period prior to pollination. The beginning and ending dates and the duration of the main pollen season (MPS) were also analyzed. Even though both families are anemophilous, the presence of their pollens in the air was low. The annual accumulated daily concentrations were in the range 1.8–15.8 for Juncaceae and 111.8–473.9 for Cyperaceae—values far lower than any other anemophilous pollen type. The Cyperaceae pollen concentration peaked between 09:00 and 12:00. The meteorological factor most closely related to its daily variations was found to be the wind direction, showing that location of the sources is of great importance. The results lend support to the hypothesis of a limitation of allogamous reproduction in favour of vegetative multiplication in both families. Nevertheless, the principal source of the airborne Cyperaceae pollen was found to be Scirpus holoschoenus, whose pollen is distinguishable from the rest. Hence, because of its large production of pollen, this species can be characterized as anemophilous and allogamous. Rainfall in the preceding autumn seemed to be responsible for the amount of Cyperaceae pollen in the air, since a lack of rain was found to be associated with lower densities in the traps. For the Juncaceae, it seems that the temperatures of the preceding December constituted the most limiting meteorological parameter.     

Isolation and characterization of two novel ethanol-tolerant facultative-anaerobic thermophilic bacteria strains from waste compost

In a search for potential ethanologens, waste compost was screened for ethanol-tolerant thermophilic microorganisms. Two thermophilic bacterial strains, M5EXG and M10EXG, with tolerance of 5 and 10% (v/v) ethanol, respectively, were isolated. Both isolates are facultative anaerobic, non-spore forming, non-motile, catalase-positive, oxidase-negative, Gram-negative rods that are capable of utilizing a range of carbon sources including arabinose, galactose, mannose, glucose and xylose and produce low amounts of ethanol, acetate and lactate. Growth of both isolates was observed in fully defined minimal media within the temperature range 50–80°C and pH 6.0–8.0. Phylogenetic analysis of the 16S rDNA sequences revealed that both isolates clustered with members of subgroup 5 of the genus Bacillus. G+C contents and DNA–DNA relatedness of M5EXG and M10EXG revealed that they are strains belonging to Geobacillus thermoglucosidasius. However, physiological and biochemical differences were evident when isolates M5EXG and M10EXG were compared with G. thermoglucosidasius type strain (DSM 2542^T). The new thermophilic, ethanol-tolerant strains of G. thermoglucosidasius may be candidates for ethanol production at elevated temperatures.     

Blooms of the invasive ctenophore, <Emphasis Type="Italic">Mnemiopsis</Emphasis> <Emphasis Type="Italic">leidyi</Emphasis>, span the Mediterranean Sea in 2009

Blooms of the invasive ctenophore, Mnemiopsis leidyi, occurred in 2009 along the Mediterranean Sea coasts of Spain and Israel. This voracious zooplanktivore spread throughout the Black Sea basin after its introduction in the early 1980s, throughout northern European coastal waters, and now occurs throughout the Mediterranean Sea. M. leidyi occurred throughout the summer along the entire Catalan Spanish and Israeli coasts in 2009. Those locations had high temperatures (18–26°C) and salinities (37–38) during the blooms. The patterns of abundance of large jellyfish along the Catalan coast were unusual in 2009, with low numbers during July, August, and September when ctenophores were abundant. Small populations of those potential predators and food competitors of M. leidyi could have contributed to the ctenophore bloom. The identity of the ctenophores from Spain and Israel was confirmed as M. leidyi by molecular analysis based on DNA sequencing of the nuclear internal transcribed spacer (ITS) regions. This is the first molecular confirmation of M. leidyi in the Mediterranean Sea. Most ctenophores had an ITS genotype previously found in M. leidyi from other invaded regions (the Black, Azov, and Mediterranean seas), as well as native regions in the United States, suggesting common ancestry. Based on the circulation patterns of Mediterranean surface waters and shipping activities, we conclude that the spread of M. leidyi in the Mediterranean probably resulted from re-introductions by ballast water transport and subsequent distribution by currents. We also conclude that the near-simultaneous blooms in opposite ends of both the Mediterranean basins indicate that M. leidyi is resident around the Mediterranean. We discuss environmental conditions, food, and predators of M. leidyi in both regions that would influence the future effects of this voracious consumer on the pelagic food web of the Mediterranean Sea.     

Effect of carbon and nitrogen sources, pH and temperature on in vitro culture of several isolates of Amanita caesarea (Scop.:Fr.) Pers.

Several isolates were obtained from sporocarps of Amanita caesarea (Scop.: Fr.) Pers. associated with Quercus suber and Castanea sativa coming from the southwest of Spain. Culture conditions were optimized for these isolates. The largest radial growth was obtained at pH 6–7, and optimal growth temperature was 24–28°C depending on the isolate. Albumin bovine and nitrate produced the largest patch size diameters, but the greatest mycelium dry weight yields were obtained with ammonium. Mannitol produced the largest radial growth, and mannitol and glucose yielded the biggest mycelium dry weights. Although variations in growth behaviour between isolates were observed, only one internal spacer sequence–restriction fragment length polymorphism type was obtained.