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1.
A new species of Batillipedidae, Batillipes spinicauda, has been found in subtidal sand sediments collected in Orosei Gulf (Sardinia, Tyrrhenian Sea). The most important peculiarities of the new species are the shape of the primary clavae, lateral processes and caudal apparatus. In the same samples, B. littoralis Renaud-Debyser, 1959 and Orzeliscus belopus Du Bois-Reymond Marcus, 1952 were found.  相似文献   

2.
Since 1980, a large program of environmental studies has been carried out along the central part of the eastern Tyrrhenian Sea, and its adjacent shoreline. The general sedimentological, biological and geochemical characteristics of this continental shelf area have been reported elsewhere (Zurlini & Damiani, 1983). In this paper, the processes responsible for the transport of terrigenous particulate matter are considered together with the influence of this particulate matter on the benthic communities of the area.Two rivers, the Garigliano to the north and the Volturno to the south, determine the extent of major environmental sub-zones in the gulf of Gaeta. The first, influenced by the Garigliano River, is restricted to the northern and inner part of the gulf, where morphological and hydrodynamical conditions favour the accumulation of suspended matter; benthic communities are stressed, mainly due to high rates of siltation. The second sub-zone is mainly influenced by the Volturno River, which affects a very large area, spreading both north and south along the coast and up to 15 km offshore.Measured levels of trace elements are considered to be close to natural concentrations. Anthropogenic contamination appears to be related to the effects of agricultural practices on the alluvial plains and to the presence of urban settlements.  相似文献   

3.
The sea urchin Paracentrotus lividus (Lamarck) (Echinodermata: Echinoidea) is an Atlanto-Mediterranean species abundant in the littoral zone, where it occurs in the sublittoral down to 20 m. The aim of our work is to investigate the genetic patterns of P. lividus along the South Tyrrhenian coasts. Five specimens were collected in six localities, from the Gulf of Naples and the Cilento coast. The nuclear rDNA ITS2 spacer and the two mitochondrial genes 16S and COI were used for the analysis. The three markers utilised did not show any structure among populations from the Gulf of Naples. All populations appear to be polyphyletic, with Cilento samples more differentiated from the others. This suggests the existence of phylogeographic structure at larger geographic scale. Absence of genetic structure has been interpreted taking into consideration theoretical dispersal of the planktotrophic larvae, which can survive for 4–8 weeks before settlement, marine current patterns and persistence of the species in the area.  相似文献   

4.
A total number of 40 potentially toxic microalgae and 5 taxa causing discolorations have been identified along the coasts of the Campania region (South Tyrrhenian Sea, Mediterranean Sea). This number is based on results of over 20 years of research at a coastal station in the Gulf of Naples, 4 years of monitoring activity along the Campania coasts and of a series of scattered and sporadic observations. Several species of the recently erected genera Karenia and Takayama are reported for the first time in the area. Information on the period of highest abundances or most probable period of occurrence indicates the late spring and summer as the periods of maximum risk of harmful events. Despite the variety of potentially toxic species, no human health problems nor fish kills have ever been recorded in Campania. The reasons for this apparent paradox are probably to be found in the ecological factors that regulate the abundance, toxicity and spatial distribution of the potentially harmful species and reflect as well the relatively low number of aquaculture plants in the area.  相似文献   

5.
6.
The stomach contents of 196 razorfish ( Xyrichthys novacula ), collected in the Tyrrhenian Sea (Ponza Island, Italy) between July and December 1994, were examined in order to assess the diet and to analyse size-related dietary variation of the species. The diet of X. novacula showed a strict relationship with well-sorted fine sand (SFBC) benthic species, mostly Mollusca and Echinodermata, as pointed out by the analysis at the specific level of the stomach contents. Mollusca Pelecipoda, essentially Acanthocardium tuberculatum and Echinodermata, with Echinocardium cordatum , made up 90% of the volume of prey of X. novacula. Mysidacea and Gastropoda were frequent but volumetrically less important. The study showed that male and female X. novacula were not effectively segregated by trophic dimension in the study area. The niche overlap between males and females in prey composition was pronounced, as evidenced by the significantly high values of Schoener's index with larger males that showed a greater tendency towards predation of large prey. The increment in length (L.I.) in males, despite a decrease in the percentage body weight increment (B.W.I.), could represent the result of a male reproductive feature: the lack of sperm competition allows the males much more energy to devote to growth than do that of the females of this species.  相似文献   

7.
Monitoring and management of Mediterranean trawling requires a multispecies and ecosystem-based approach. Over the last 20 years studies on diversity and distribution of fish communities have been carried out by ecologists and applied to different ecosystems. Until now, very little information has been available on the Southern Tyrrhenian Sea. The aim of this work is: to analyse the structure of fish demersal assemblages, on a temporal (10 years) and spatial scale using a multivariate approach; to analyse, across space and time, the pattern of biodiversity by means of univariate indices; to identify areas supporting high values of diversity and evenness by a Geographical Information System (GIS) method. The analysis of 249 hauls from ten trawl surveys carried out between depths of 30 and 750 m in the South Tyrrhenian Sea yielded a total of 164 fish species. Multidimensional scaling ordination showed four groups distributed according to the depth gradient: a coastal group (0–100 m depth), a group in the lower part of the continental shelf (101–200 m), an epibathyal group (201–500 m) and the last one derived from hauls made in the middleslope (501–800 m). There were no differences, between years, protected and unprotected areas and geographical sectors. The whole study area was characterised by diversity values which were quite heterogeneous. The persistence index was generally low. Results could be useful from an ecological point of view and for the management of fishery activities.  相似文献   

8.
The palaeontological, geochemical and mineralogical records of core GNS84-C106 were analysed in order to reconstruct palaeohydrological changes and palaeoproductivity patterns in the Gulf of Salerno for the last 34 kyr. This approach, including compositional analysis of planktonic and benthic assemblages, gave an insight into the relationships between continental, sea surface and bottom environmental changes. The main source of variability of planktonic and benthic assemblages is related respectively to sea surface temperature and palaeobathymetry. Interrelated changes in surface salinity, nutrients, density gradient in the water column and organic fluxes at the bottom act as a secondary factor controlling the composition of both planktonic and benthic assemblages. The highest palaeoproductivity rates were reached during an interval spanning from late glacial to Middle Holocene, in conditions of enhanced continental run-off. During the Early and Middle Holocene, reduced surface salinity and density stratification were also coupled with the development of a deep chlorophyll maximum and enhanced flux or organic matter at the bottom. From about 6.5 kyr B.P. onward, a sharp reduction in palaeoproductivity took place, coupled with an increase in surface salinities.  相似文献   

9.
A new species, Festucalex armillatus sp. n., is described from the littoral zone of Hainan Island (China). The species differs from other species of the genus in a combination of the following characters: trunk rings 16–17 + 31–32, two prepectoral ridges present, lateral trunk ridge terminated on the third or fourth caudal ring, snout comparatively short and very deep, and a characteristic pattern composed of four wide dark bands on the head and numerous narrow transversal dark bands on a light background of the trunk.  相似文献   

10.
A new genus and species Zagadkogobius ourlazon gen. et sp. nov. characterized by an unusual (for the subfamily Ptereleotrinae) combination of characters is described. A single specimen was collected at a depth of 73 m in the southwestern South China Sea to the south of the Anambas Islands. Based on the combination of characters, the new genus is most similar to the genus Nemateleotris. However, the species of the latter genus are associated exclusively with coral reefs. A key to the genera of the subfamily Ptereleotrinae is presented.  相似文献   

11.
12.
Late Miocene Lago-Mare macrofossiliferous sediments were recovered in the northeastern Tyrrhenian Sea by dredging the continental slope off Gorgona Island, Tuscan Archipelago, at 300-470 m depth. The fossil assemblage consists of a rich lymnocardiid bivalve fauna dominated by Pontalmyra ex gr. P. incerta (Deshayes), associated with Dreissena ex gr. D. rostriformis (Deshayes), Pontalmyra cf. partschi (Mayer), “Limnocardium” sp., the gastropods Melanopsis narzolina (D’Archiac), Melanopsis sp. and cf. Saccoia sp. All bivalve taxa recognized at species level are of Paratethyan (Pontian) affinity and widespread in the Late Miocene of the Mediterranean Basin while M. narzolina has so far only recorded from the Mediterranean Basin. This finding represents the most diverse Lago-Mare macrofauna reported thus far from any submerged location in the Mediterranean Basin and documents that the post-evaporitic Cusercoli Formation contributes to the syn-rift neoautochthonous units of this sector of the Northern Tyrrhenian Sea.  相似文献   

13.
Megasolena dongzhaiensis n. sp. was collected from the intestine of Scatophagus argus (Linnaeus) (Perciformes: Scatophagidae) from the Dongzhai Bay (110 degrees 32'-37'E, 19 degrees 51'-20 degrees 1'N), Hainan Province, China. It resembles Megasolena acanthuri Machida and Uchida, 1991 in having larger body size, but it differs from the latter species in having an oral sucker that is larger, instead of smaller, than the acetabulum (sucker length ratio 1:0.456-0.494, and width ratio 1:0.61-0.65 in M. dongzhaiensis n. sp., as opposed to 1:1.3-1.7 in M. acanthuri). Moreover, the cuticle is spinose rather than aspinose; there is a band of circular muscle in the pharynx, and its eggs are smaller instead of larger (0.062-0.068 x 0.036-0.039 in M. dongzhaiensis n. sp., compared with 0.087-0.103 x 0.058-0.072 in M. acanthuri). Finally, the intestinal bifurcation is anterior, instead of dorsal, to the acetabulum. It resembles other species of Megasolena Linton, 1910 in having oral sucker larger than the acetabulum, and in having a circular muscle band in the oral sucker and pharynx, but it differs in having a larger body and smaller eggs. This is the first record of a Megasolena species from ray-finned fishes as well as in China.  相似文献   

14.
A sample of 67 European hake Merluccius merluccius were examined to highlight the ingestion of microplastics in the Tyrrhenian Sea. In all samples, 31 black fibres were found in the stomach contents corresponding to 46.3% of the specimens. The data presented here could be important for the implementation of the EU Marine Strategy Framework Directive in Mediterranean waters.  相似文献   

15.
Two exopolysaccharide (EPS)-producing strains of the diatom Navicula, were isolated from benthic and pelagic mucilaginous aggregates sampled in the Tyrrhenian Sea and cultured under laboratory conditions. The amount of carbohydrate formed over the growth period and on a per cell basis was quite similar. However, the benthic strain showed a preferential synthesis of the bound (i.e., cellular and capsular) carbohydrate fraction, whereas the pelagic strain preferentially synthesised soluble, polymeric carbohydrates. The polysaccharides released into the medium by the two strains showed the same qualitative monosaccharidic composition, being constituted by two acidic and six neutral sugars. It is suggested that the difference between the benthic and the pelagic strain in the synthesis of bound or soluble carbohydrates may be related to the different role of these compounds in the particular habitats of the strains.  相似文献   

16.
Journal of Ichthyology - Among the ten species of anemonefish symbiotic anemones recorded for Vietnam, we have distinguished two main species, Entacmaea quadricolor and Stichodactyla mertensii,...  相似文献   

17.
Benthic foraminiferal assemblages in 127 samples, collected at water depth, ranging between 15 and 184 m on the Southern Tuscany continental shelf off the Ombrone River were analysed. Statistical analyses (Cluster and Principal Component Analysis) performed on the 48 most abundant species (>5%) and sedimentological data led to the identification of three clusters related to the size of grain sediment (sand, silt or clay). Q-mode cluster analysis singled out six groups, corresponding to six distinct foraminiferal assemblages: a typical infralittoral assemblage (15-39 m) on sandy silt, clayey silt or silty clay, dominated by Ammonia and Elphidium species, with Eggerelloides scabrus, Rectuvigerina phlegeri and Valvulineria bradyana; a second assemblage (24-78.5 m) associated with vegetated environments or sandy bottoms (Elphidium crispum, Rosalina bradyi, Asterigerinata mamilla, Neoconorbina terquemi, and Tretomphalus concinnus); a third assemblage recognised between 30 and 90 m water depth and characterised by the dominance of the opportunistic species V. bradyana (related to silty bottoms), with Bulimina marginata, R. phlegeri, Ammonia inflata and Ammonia beccarii as other common taxa; an upper circalittoral assemblage (70-100 m) on silty clays, containing B. marginata, Cassidulina carinata and V. bradyana; a lower circalittoral assemblage (95-177 m) on clayey bottoms, with B. marginata, Textularia bocki and Uvigerina mediterranea; and finally, a second lower circalittoral assemblage (104-184 m) on clayey sediments, dominated by two Uvigerina species (U. mediterranea and Uvigerina peregrina), with Sphaeroidina bulloides and B. marginata. The typical V. bradyana assemblage, characterised by relatively low diversity and high dominance, marks the most eutrophicated area running parallel to the coast. The spatial distribution of assemblages is closely associated with sea-bottom sedimentary environments and bathymetry but it is also probably influenced by the outflow of the Ombrone River. The composition, structure and distribution of V. bradyana assemblage suggest an environmental model, useful for paleogeographic reconstruction in areas characterised by a river mouth and a closed morphological setting typical of a nutrient-trap.  相似文献   

18.
Antithamnion makroklonion sp. nov. is described from Elat, Gulf of Aqaba (Gulf of Elat) in the Red Sea, where vegetative, spermatangial, and tetrasporangial specimens were found growing in the upper sublittoral zone. The new alga belongs to a group of Antithamnion species characterized by distichous-alternate ramification of branches, sessile tetrasporangia, and decussately arranged laterals along the bearing axis. It shows a unique combination of distinctive features, including the proximal development of gland cells on elongate branchlets that overtop the parent branch. In addition to the characteristic position, and in contrast to congeners, gland cells of A. makroklonion often have a large and prominent cytoplasmic band and one or two vacuoles. Morphological features of A. makroklonion and eight related species are tabulated and the characteristics of the new species are discussed.  相似文献   

19.
The length–weight relationships of four fish species: Lophiomus setigerus (Vahl, 1797), Uranoscopus oligolepis Bleeker, 1878, Cynoglossus oligolepis (Bleeker, 1855), and Cynoglossus arel (Bloch & Schneider, 1801) were determined. Specimens were collected from the Beibu Gulf in the South China Sea by using bottom trawl nets (mesh size 4.0 cm, at a towing speed about 3 knots) in the seasonal investigations from August 2010 to May 2011. The values of parameter b of these four species ranged from 2.982–3.489 and remained within the normal range of 2.5–3.5.  相似文献   

20.
Anisakis simplex sensu stricto (s.s.), Anisakis pegreffii, Anisakis berlandi (=A. simplex sp. C), and Anisakis typica are the 4 major species of Anisakis type I larvae. In the Republic of Korea (Korea), A. pegreffii, A. berlandi, and A. typica larvae in fish hosts has seldom been documented. In this study, molecular analysis was performed on Anisakis larvae from the sea eels (Astroconger myriaster), the major source of human anisakiasis in Korea, collected from Tongyeong City, a southern coastal area of Korea. All 20 sea eels examined were infected with Anisakis type I larvae (160 larvae; 8 per fish). Their species were analyzed using PCR-RFLP patterns and nucleotide sequences of internal transcribed spacers (ITS1, 5.8 subunit gene, and ITS2) and mitochondrial cytochrome c oxidase 2 (cox2). Most (86.8%; 112/129) of the Anisakis type I larvae were A. pegreffii, and 7.8% (10/129) were A. typica. The remaining 5.4% (7/129) was not identified. Thus, A. pegreffii is the major species of anisakid larvae in sea eels of the southern coast of Korea.  相似文献   

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