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During May and June 2000, for the first time, benthic samples were collected from 43 stations in the northern Gulf of Mexico deep sea that included seven transects along the northern continental slope and abyssal plain ranging in depth from 625 to 3159 m. A total of 54 tardigrades (36 identified) were extracted from samples, ranging in depth from 625 to 3150 m. Collected tardigrades belong to five genera and represented eight species, Angursa bicuspis abyssalis (two specimens from 1401 and 2020 m depth), four species of Coronarctus (29 specimens from 625 to 3159 m depth), Euclavarctus convergens (one specimen from 2743 m depth), E. thieli (one specimen from 2635 m depth), Proclavarctus sp. (one specimen from 2600 m depth), Styraconyx sp. (two specimens from 1565 and 2600 m depth). The most abundant genus was Coronarctus (80.5% of identified species) and was present in most areas sampled with the exception of the central and Mississippi trough regions and comprised four species, Coronarctus laubieri (15 specimens), C. stylisetus (one specimen), C. disparilis (three specimens) and a new species C. mexicus (10 specimens). Tardigrades were mostly found in the western regions (NW, W, WC) and in deep waters, 2290 m average depth. Analyses of tardigrade and depth collected gave a slight positive correlation (R 2 = 0.029), while analyses of tardigrade and degrees longitude resulted in a slight negative correlation (R 2 = 0.022).

A comprehensive study on the composition, structure and diversity of tardigrade communities along the Southern Apulian coast was carried out in March and September 2000. The Apulian coastline counts about 820 km and includes a wide variety of natural environments such as Torre Guaceto, Laghi Alimini and Porto Cesareo and areas with high human impact such as Mattarelle (Enel power Station), Brindisi Harbour and Torre Mozza with its fish processing industry. The research was carried out only in the subtidal zone but in different kinds of sediments: coarse, medium, fine and very fine sand, sand in Posidonia meadows, coarse organogenous debris and mud. Seventeen stations were sampled at three different depths in two seasons: March and September, resulting in 86 samples of which 58 samples contained tardigrades. A total of 4288 specimens (2975 in March and 1313 in September) were identified to 52 species (51 in March and 36 in September). The tardigrade fauna along the Apulian coast are very rich, hosting more than 1/3 of all known arthrotardigrade species. The species found in Southern Italy belong to the arthrotardigrade families Neoarctidae (one species), Stygarctidae (four species), Halechiniscidae (42 species) and Batillipedidae (six species). Halechiniscidae is the most abundant family followed by Batillipedidae, Stygarctidae and Neoarctidae. The diversity, density and relative abundance were recorded, and the spatial variation of species diversity was statistically evaluated. Coarse sand which is found mainly at 10 m depth seems to constitute the most favourable environment, which is evident from both species number and Shannon index H. Bray–Curtis cluster analysis combined with ordination by principal component analysis discriminate the species composition in three evident main clusters: coarse sand, fine sand and mud. Furthermore, the particular environmental factors in areas with sulphur springs, mussel farms as well as high seasonal tourism, seem to have a considerable impact on the species composition of these areas. Riassunto Nei mesi di Marzo e Settembre del 2000 lungo le coste Pugliesi e stato realizzato uno studio approfondito sulla struttura e sulla biodiversita della Tardigradofauna. I circa 820 km di costa Pugliese includono una vasta varieta di habitat, come le Aree Marine Protette di Torre Guaceto e Porto Cesareo, aree a largo impatto umano come Laghi Alimini e Gallipoli (alta densita di turismo stagionale), Mattarelle (Stabilimento produzione elettrica Enel), Brindisi (zona del porto), Torre Mozza e Castro industrie ittiche (allevamento mitili) e Santa Cesarea Terme zona termale (acque sulfuree). La ricerca ha interessato solo il settore subtidale in zone con diverso tipo di sedimento: sabbia grossolana, sabbia fine, sabbia molto fine, sabbia di praterie di Posidonia oceanica, detrito organogeno e fango. Sono state investigate 17 stazioni a 3 diverse profondita e in 2 diversi periodi: Marzo e Settembre per un totale di 86 campioni di cui 58 contenenti tardigradi. Sono stati raccolti 4288 esemplari (2975 a Marzo e 1313 a Settembre) e sono state identificate 52 specie (51 a Marzo e 36 a Settembre). La tardigradofauna lungo le coste Pugliesi e molto ricca e comprende 1/3 di tutte le specie di Arthrotardigrada conosciute. Le specie rinvenute nel Sud Italia appartengono alle famiglie di Arthrotardigrada Neoarctidae (1 specie), Stygarctidae (4 specie), Halechiniscidae (42 specie) e Batillipedidae (6 specie). Se ne deduce pertanto che Halechiniscidae e la famiglia piu abbondante, seguita dai Batillipedidae, Stygarctidae e Neoarctidae. La diversita, la densita e la relativa abbondanza sono state calcolate assieme alla variazione spaziale delle specie. La sabbia grossolana, maggiormente presente a 10 m di profondita, sembra costituire l’ambiente piu favorevole al rinvenimento della tardigradofauna. Tutto questo e reso evidente dall’alto numero di esemplari e specie rinvenuti. La Cluster-analisi di Bray–Curtis combinata con la PCA (Principal Component Analysis) ha permesso di mettere in evidenza, relativamente alla composizione della fauna 3 clusters principali: sabbia grossolana, sabbia fine e fango. Inoltre fattori ambientali particolari quali sorgenti sulfuree, mitilicultura, zone ad alto turismo stagionale, sembrano avere un considerevole impatto sulla composizione della fauna in queste aree.

Persistent organochlorines, such as polychlorinated biphenyls including coplanar congeners and DDT compounds were measured in the liver of different species of mollusc cephalopods: broadtail squid (Illex coindetii), horned octopus (Eledone moschata) and spider octopus (Octopus salutii) collected in two different areas of the Adriatic Sea (central and southern Adriatic Sea). The concentration of PCBs exceeded DDT ones in horned octopus (PCBs: 617.0 ngg(-1) lipid weight, DDTs: 188.0 ngg(-1) lipid weight) and in spider octopus (PCBs: 590.0 ngg(-1) lipid weight, DDTs: 293.0 ngg(-1) lipid weight), while in broadtail squid PCB load (748.0 ngg(-1) lipid weight) was similar to those of DDTs (514.5 ngg(-1) lipid weight). No significant difference in PCB levels was observed among species, while DDT concentrations were higher in broadtail squid than in horned octopus and spider octopus. DDTs composition showed slight differences in relation to species, thought p,p'-DDE was the predominant compound in all cephalopod species (broadtail squid: 88.1%, horned octopus 94.1%, spider octopus: 97.5%). PCB isomer profiles were similar among species being hexachlorinated isomers the most abundant, followed by penta- and heptachlorobiphenyls, while tri- and tetrachlorobiphenyls made up a small percentage of the total PCB residues. Regarding coplanar congeners, non-ortho PCBs were below the detection limit in all samples and the 2,3,7,8-TCDD toxic equivalent (TEQ) concentrations were very low. The influence of biological and ecological factors (size/weight and location) on the bioaccumulation of organochlorine compounds has been discussed.

Total mercury and methylmercury concentrations were measured in the muscle tissue of different fish species from the Adriatic Sea to ascertain whether the concentrations exceeded the maximum level fixed by the European Commission. Large species-dependent variability was observed. The highest total mercury mean concentrations were in benthic (0.20-0.76 microg g(-1) wet wt) and demersal fish (0.22-0.73 microg g(-1) wet wt), while pelagic species showed the lowest levels (0.09-0.23 microg g(-1) wet wt). In 15% of frost fish, in 42% of skate and in 30% of angler fish samples total mercury concentrations exceeded the maximum level fixed by the European Commission (Hg = 1 microg g(-1) wet wt); for the species for which the maximum level was set to 0.5 microg g(-1) wet wt, concentrations exceeding the prescribed legal limit were observed in 6.4% of bokkem, in 6.6% of pandora, in 20% of megrin, in 12.5% of four-spotted megrim, in 16% of striped mullet, in 5.0% of forkbeard and in 5.3% of picarel samples. In all the different species, mercury was present almost completely in the methylated form, with mean percentages between 70 and 100%. Weekly intake was estimated and compared with the provisional tolerable weekly intake recommended by the FAO/WHO Expert Committee on Food Additives. A high exposure was associated with the consumption of only skates, frost fish and angler fish, thought the consumption of the other species, such as, megrim, four spotted megrim, red fish striped mullet and forkbeard, resulted in a weekly intake slightly below the established provisional tolerable weekly intake.

Owing to technical problems and difficult taxonomic identification, meiofauna have been generally less studied than macrofauna. However, the role of meiofauna in marine ecosystem functioning, and their effective and rapid response to anthropogenic alterations and climatic changes have recently been acknowledged, leading to increasing scientific and applied interest. At present, systematic and biogeographic knowledge of the meiofauna of the Adriatic Sea is extremely heterogeneous, because most of the data are limited to a few taxa and the sampled areas are scattered, being located mainly in the coastal areas of the northern basin. Analysis of the composition and distribution of meiobenthic groups in the Adriatic Sea highlights the presence of several endemisms. Meiofauna also include bioindicator taxa, which allow assessment of the quality of marine sediments; this is particularly useful in systems characterised by the synergistic effect of different forms of anthropogenic impact, such as the Adriatic basi...

The onset of instability and subsequent development of cells on spherically expanding flames is examined theoretically. The model used accounts for both hydronamic and diffusive-thermal effects and, in contrast to earlier theories, is valid for variable transport properties over a wide range of equivalence ratios. The analysis yields predictions for a number of flame properties, including growth rate of small disturbances, critical flame size for the instability onset, cell size beyond the threshold, and an estimate of the speed of the developing turbulent flame. It is shown that results using the more realistic temperature-dependent transport coefficients are more commensurate with experimental data concerning the critical conditions, that is, flame size or Peclet number, at the transition from one burning regime to another.

A new species of Stygarctidae, belonging to the genus Pseudostygarctus McKirdy et al., 1976, Pseudostygarctus apuliae, was found in subtidal sediments of Porto Colombo, near Bari (Adriatic Sea) and...

Concentrations of trace elements (Hg, Cd, Pb, Zn, Cu, Fe, and Se) in different organs and tissues (liver, kidney, muscle tissue, spleen, heart, lung, and fat tissue) of loggerhead turtles Caretta caretta from eastern Mediterranean Sea were determined. The highest levels of mercury and cadmium were found in liver (Hg: 0.43 microg g(-1) wet weight; Cd: 3.36 microg g(-1) wet weight) and kidney (Hg: 0.16 microg g(-1) wet weight; Cd: 8.35 microg g(-1) wet weight). For lead the overall concentrations were low and often below the limit of detection. Copper and selenium tended to be higher in liver than in other tissues and organs, while for zinc the concentrations were quite homogenous in the different organs and tissues, except fat tissue (64.7 microg g(-1) wet weight) which showed a higher accumulation of this element. For iron the greatest concentrations were observed in liver (409 microg g(-1) wet weight) and spleen (221 microg g(-1) wet weight).

Polychlorinated biphenyls including coplanar congeners were measured in the liver of different species of skates and ghostsharks. The mean concentrations of PCBs in skates (314 ng/g wet wt) were comparable with those in ghostsharks (285 ng/g wet wt). The specific analysis of PCB congeners in skates hepatic tissue revealed a profile dominated by hexa-, penta-, and heptachlorinated congeners followed by trichlorobiphenyls, tetra- and decachlorobiphenyls. A different profile dominated by hexa-, tri-, and pentachlorinated congeners, followed by heptachlorobiphenyl and decachlorobiphenyls was found in ghostsharks liver. The estimated 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) of coplanar PCBs in skates and ghostsharks were 0.48 and 0.33 pg/g wet weight, respectively, with mono-ortho congeners PCB105, 118 and 156 contributing more than 90% to the TEQs. Keywords: Skates, Ghostsharks, PCB congeners, TEQs

The muscle tissue of different species of fish was analyzed for polychlorinated biphenyls (PCBs) in order to estimate the daily intake of these contaminants. Contamination levels among the different species varied between 108 and 678 ng/g lipid weight. Isomer-specific analysis in the muscle tissue of the various fish revealed a profile dominated by hexa- and pentachlorobiphenyls, followed by hepta- and tetrachlorobiphenyls. Other congeners, including those with fewer than four or more than nine chlorine atoms, were below the instrumental limit of detection in all samples. PCB dietary intake was below the range of 1 to 4 pg 2,3,7,8-tetrachloro-p-dioxin equivalents per kg body weight per day set by the World Health Organization. From a public health point of view, there is no indication of important risks associated with the consumption of these seafoods.

Information about Indian Ocean tardigrades is quite scarce and in most cases refers to species in coastal coralline sediment and occasionally in abyssal mud. The present data concern species found in the intertidal sand of Coco and La Digue Islands in the Seychelles, previously unsampled for tardigrades, as well as species in subtidal sediment found at depths ranging between 1 and 60 m off the shores of the Maldive Atolls. These sediments are all very similar and consist of heterogeneous coralline sand, moderately or scarcely sorted. Sixteen species (three new to science) were found in the Seychelles, belonging to Renaudarctidae, Stygarctidae, Halechiniscidae, Batillipedidae and Echiniscoididae. Diversity and evenness data are also interesting, with maximum values of H' = 2.59 and of J = 0.97. In the Maldives 25 species were found (two new to science) belonging to Neostygarctidae, Stygarctidae, Halechiniscidae and Batillipedidae. Such a number of species, despite the low percentage of tardigrade fauna (only 0.6% of the total meiofauna), contributes to the high values of both diversity and evenness, with H' ranging between 1.5 and 2.6 and J between 0.6 and 1. The Indian Ocean tardigrade fauna currently numbers 31 species of Arthrotardigrada and 2 species of Echiniscoidida. In the present study, Arthrotardigrada are the most abundant and all the families are present except Neoarctidae. Halechiniscidae is present with all the sub-families (except Euclavartinae), thus contributing to the high diversity values. Furthermore, 18 species, representing more than 50% of the total marine tardigrade fauna, are new records for the Indian Ocean, including five species new to science.

An investigation on the taxonomy and ecology of marine tardigrades was carried out in different intertidal and subtidal sites along the coasts of Sardinia (Italy). Particle size analysis of sediments revealed medium or medium-fine intertidal sands and coarse subtidal sands, the latter mainly formed by coralligenous debris. The systematic study was particularly relevant, leading to the identification of 25 species, of which 9 are new records for Sardinia, and 2 are new to science. With these new findings, the total number of species for Sardinia adds up to 47. The species found belong to the families Halechiniscidae (16 species; abundance 2 to 263 ind. 10 cm-2), Batillipedidae (6 species; abundance 2 to 574 ind. 10 cm-2) and Stygarctidae (3 species; abundance 0 to 13 ind. 10 cm-2). The present data confirm the existence of a remarkable diversity, both of intertidal and subtidal tardigrade fauna. Generally, the prevalently siliceous intertidal sands host a few number of species (sometimes with many individuals), while the subtidal sediments, which were mainly calcareous, show a higher number of species often with low density. In fact, in the intertidal sediments only 11 species were found, 5 belonging to Halechiniscidae and 6 to Batillipedidae. In the subtidal sediments, there was a much wider variety; Halechiniscidae showed the highest number of species (16), compared to the remaining families, while Stygarctidae, which were present only in subtidal sediments, accounted only for 3 species. In the intertidal zone the highest value of the diversity index (H') was 2.1 and in the subtidal zone it was 3.3.