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1.
Polychaete assemblages associated to the sponge Geodia cydonium were investigated at two sampling sites in the Mediterranean Sea: Porto Cesareo Basin (Apulia) and Marsala Lagoon (Sicily), both characterized by sheltered hydrodynamic conditions. Samples were seasonally performed during 1997, in order to compare the assemblages coming from the two localities studied, considering separately the internal and external tissues of the sponge, and with the aim of evaluating the influence of sponge size on polychaete colonization. The examined sponge is characterized by a peculiar stratification of its tissues: an external thick and hard layer, the cortex, and an internal softer one, the choanosome. Statistical analysis showed that this was the main factor controlling polychaete assemblage, with the internal tissue, less rich and diversified, appearing impoverished with respect to the external layer. A similarity in species composition was observed between sites, even though some differences were evidenced in the abundance of some species, mainly reflecting differences in local environmental conditions. Species richness and density increased with the increasing sponge size. Such a situation is particularly evident at Porto Cesareo, where sponges are covered by an algal layer which is particularly rich on the largest specimens, thus suggesting that most of the species of polychaetes were linked more to the neighbouring environment than to the sponge itself. 相似文献
2.
P. Abelló N. Ungaro C.-Y. Politou P. Torres E. Roman P. Rinelli P. Maiorano G. Norrito 《Hydrobiologia》2001,449(1-3):187-192
Data on the distribution and biology of the deep-sea portunid crab Bathynectes maravigna are reported for the Mediterranean Sea, based on several fisheries research surveys. Densities are low and, therefore, biological data are scarce. In the western Mediterranean, the species is much commoner in Alborán Sea than in the Catalano-Balearic Sea. Occurrences are also scarce in the southern Adriatic and northwestern Thyrrenian Sea, as well as in the Ionian Sea. The Alborán Sea and the seas surrounding the southern Italian peninsula are the areas where densities are the highest. The occurrence depth range was found to be 245–786 m, but most of the occurrences took place deeper than 500 m. Sizes ranged between 9 and 51 mm carapace length in males and between 12 and 51 mm in females. Ovigerous females have been only reported in October–December and March–May. Eighty three percent of both males and females are right-handed. Sexual dimorphism was present in cheliped length with males having longer chelae than females. The species appears to be much commoner in those areas where Atlantic influence is the highest. 相似文献
3.
Regino Zamora Manuel Jamilena Manuel Ruiz Rejón Gabriel Blanca 《Plant Systematics and Evolution》1996,200(1-2):41-60
Two species ofPinguicula (P. submediterranea andP. mundi) are newly described from the south and east of the Iberian Peninsula. We analysed morphometric, cytogenetic, RAPD, ecological, and breeding system data to support the distinctness of these taxa.Pinguicula submediterranea andP. mundi are both hexaploid (2n = 48), a chromosome number previously not reported for the genus. Biometric, cytogenetical and molecular results distinguishP. submediterranea andP. mundi from otherPinguicula species, and from each other.Pinguicula mundi is predominantly outbreeding, whereasP. submediterranea both inbreeds and outbreeds.Pinguicula submediterranea andP. mundi appear to be isolated reproductively, although gene flow between the allopatricP. submediterranea andP. mundi is unlikely. BothP. submediterranea andP. mundi are threatened with extinction because suitable habitats are diminishing in size, or even disappearing, due to current aridity in the region. 相似文献
4.
Four new species of Metepsilonema are described from sublittoral stations from the Channel and are mainly characterized: M. volutum sp.nov. by the large body size for the genus up to 460 m, 118–121 well overlapping annuli and wide multispiral amphids; M. amphidoxum sp.nov. by 127–133 shortly overlapping annuli and sexual dimorphism in amphid size; M. comptum sp.nov. by 133–140 non-overlapping annuli, anteriormost annuli provided with a wide lumen and borders ornamented with ridges and M. corrugatum sp.nov. by 108–111 overlapping annuli provided with ridges). Additional information is provided for M. callosum together with a discussion on intraspecific variability. A new species of Metepsilonema spec. based on females only, is described but remain unnamed. M. comptum sp.nov. and M. corrugatum sp.nov. are also occurring in the Mediterranean Sea. A polytomous key to species level is presented. 相似文献
5.
Sex-related rostral variability was studied in the aristeid shrimp Aristeus antennatusfrom the Eastern Ionian Sea (Mediterranean). Shrimps were collected on a monthly basis from December 1996 to November 1997 using a commercial bottom trawl in a depth range of 446–728 m. Female relative growth of rostrum proved to be negative allometric both seasonally and in the pooled annual data set. Males on the other hand, showed no or negative correlation of rostrum length with size. Mature males with short rostra dominated in the male population all year around. The appearance of males with long and intermediate rostra during winter, which disappear thereafter in favour of those with short rostra, indicates that rostrum shortening takes place during the end of winter. The increase of mated females during spring supports the hypothesis already addressed by other authors on the function of the male short rostrum in this species mating behaviour. Nevertheless, the paucity, in comparison to other Mediterranean populations, of males with long or intermediate rostra could indicate that for the bulk of the male population, the process of rostrum shortening in the Eastern Ionian Sea occurs outside the geographical locality or depth range sampled. 相似文献
6.
Farjallah S Merella P Ingrosso S Rotta A Slimane BB Garippa G Said K Busi M 《Parasitology international》2008,57(4):437-440
Specimens of Contracaecum rudolphii Hartwich, 1964 (Nematoda: Anisakidae) from Phalacrocorax aristotelis (Linnaeus) from the Archipelago of La Maddalena (Sardinia, western Mediterranean Sea) were characterised genetically and compared with C. rudolphii A sensu D’Amelio et al. 1990 and C. rudolphii B sensu D’Amelio et al. 1990 from Phalacrocorax carbo sinensis (Blumenbach) from north-eastern Italy, and with C. rudolphii C sensu D’Amelio et al. 2007 from Phalacrocorax auritus (Lesson) from west-central Florida, USA. The sequencing of the small subunit of the mitochondrial ribosomal RNA gene (rrnS) and by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) analysis of the same gene and of the internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA) allowed the identification of all specimens of C. rudolphii from P. aristotelis as C. rudolphii A. The results confirmed that the definition of genetic markers, following the analysis of nuclear ribosomal and mitochondrial DNA, provides quick and practical diagnostic tools for the detection of the 3 sibling species of C. rudolphii. The occurrence of C. rudolphii in P. aristotelis is reported for the first time from the Mediterranean area, improving the picture of the dispersal patterns of the populations of these piscivorous birds, and confirming the existence of different and isolated populations between the North and South European waters. 相似文献
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8.
Antonov AS Kalinovsky AI Dmitrenok PS Kalinin VI Stonik VA Mollo E Cimino G 《Carbohydrate research》2011,346(14):2182-2192
Seven new triterpene glycosides, erylosides R1 (1), T1 (3), T2 (4), T3 (5), T4 (6), T5 (7), and T6 (8) along with the known formoside (2) were isolated from the sponge Erylus formosus collected along the Caribbean coast of Mexico. Glycoside 1 was determined as a trisaccharide, glycoside 2 as a tetrasaccharide while glycosides 3–8 were hexasaccharide. Their carbohydrate chains were unprecedented and have never been found in oligosaccharides from other biological sources, except Erylus spp. Three carbohydrate chains in the glycosides 3 and 6, 4 and 7, 5 and 8 correspondingly are new. The glycosides 1–5 have penasterol as aglycone while glycosides 6–8 proved to be glycoconjugates of 24-methylene-14-carboxy-lanost-8(9)-en-3β-ol. 相似文献
9.
Carl-Erik Cantell 《Hydrobiologia》1988,156(1):105-113
The anatomy of an insufficiently described species of heteronemertine, Cerebratulus hepaticus, is redescribed. The species is characterized by, inter alia, a cephalic lacuna with strands of longitudinal muscle fibres, a proboscis with three muscle layers, neurochord cells in the brain, a dermis in the foregut region with no or few longitudinal muscle fibres which is separated from the outer longitudinal muscle layer by connective tissue. The taxon is compared with two other Cerebratulus species, C. fuscus and C. marginatus. The material was collected at Banyuls-sur-Mer (France) in the Mediterranean. 相似文献
10.
The cavities and outer surfaces of 20 individuals of the sponge Sarcotragus muscarum collected from the Turkish Aegean coast during July–September 1993 contained a total of 148 zoobenthic species with 5299 individuals belonging to seven taxonomic groups. Among these, Polychaeta accounted for 60% of the total number of species, while Crustacea comprised 71% of the total number of individuals and 40% of the wet weight of biomass. The amphipod and decapod crustaceans Tritaeta gibbosa and Synalpheus gambarelloides, and the bivalve Hiatella arctica, were the most abundant species on the sponge samples both in terms of number of individuals and biomass values. The community structure inside the sponges was greatly influenced by the nature of the substratum around the sponge, and by the overwhelming population of the Lessepsian echinoderm Ophiactis savignyi. Number of species, biomass and diversity index values were found to be positively related to the sponge volume. Mean density and biomass of the associated taxa are 0.22 ind cm–3 and 11.63 mg cm–3, respectively. 相似文献
11.
GIORGIO BAVESTRELLO MICHELE SARÀ 《Biological journal of the Linnean Society. Linnean Society of London》1992,47(1):49-60
The taxonomic status of two sponge tnorphotypes living sympatrically in Mediterranean caves and usually ascribed to Petrosia ficiformis was elucidated on the basis of morphological, morphometric and genetic features. The two morphotypes, spherical and cylindrical, showed differences in the shape and size of spicules and in the morphology of the aquiferous system. Electrophoretic analyses demonstrated that the two morphotypes are reproductively independent and so they should be considered as distinct biological species. The spicular features allow attribution of the cylindrical morphotype to P.ficiformis and the spherical one to P. clavata. For these two species parasympatric speciation is proposed. 相似文献
12.
Selectivity experiments were carried out during trawling targeting deep-water shrimps Aristaeomorpha foliacea (Risso, 1827) and Aristeus antennatus (Risso, 1816) (Crustacea, Decapoda, Aristeidae) in the North-Western Ionian Sea (Eastern-Central Mediterranean). Different criteria were employed to analyse maturity; however, the proportion at 50% of retained, mated and mature specimens was always used to indicate the size, expressed as Carapace Length (CL, mm), at first capture (CLc), mating (CLsp) and at first maturity (CLm), respectively. In order to estimate the size at 50% maturity (CLm) for females of both species, three criteria were adopted. In particular, CLm was computed for the mature females not considering the presence of spermatophores, for the mature females with spermatophores and for the mature females intersected by the decreasing proportion with size of females without spermatophores. Three diamond stretched mesh codends of 40, 50 and 60 mm were tested using a cover of 20 mm. The 40-mm stretched mesh size (European Union legal size in the Mediterranean) was not selective for the sampled population of each species. The size at first capture (CLc), calculated in both species for the two sexes combined, increased significantly with mesh size. Even for the mesh size of 60 mm, the size at first capture was still smaller than the sizes at 50% maturity, whatever the criterion adopted. Since the differences between the size at first maturity and the sizes at first capture are greater in A. foliacea than A. antennatus, the former species appears in this respect to be more vulnerable to trawling than the latter. 相似文献
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14.
An exceptionally high abundance of Myriochele fragilis Nilsen & Holthe, 1985 (Polychaeta: Oweniidae) is reported for the Ierapetra Basin in the Eastern Mediterranean Sea from depths of 4159 and 4260 m, representing the first record outside the Norwegian and Arctic Sea and extending the depth range by more than 1600 m. Specimens are described and compared to closely related species. 相似文献
15.
The two closely related speciesLycopsis variegata andAnchusa cretica, formerly placed inAnchusa subg.Rivinia, were compared with the type species ofLycopsis andAnchusa, on the basis of a set of macro and microcharacters. The presence of only two fertile stamens as well as other peculiar characters in flower structure, androecium, gynoecium, pollen and fruit, supports the institution of the new genusAnchusella, consisting ofA. variegata andA. cretica. Karyological and eco-chorological aspects are consistent with morphological data in pointing to the autonomy of this genus, which appears characterized by autapomorphic, advanced traits. 相似文献
16.
Five species belonging to two genera of pinnotherid crabs are reported from the Yellow Sea. Two are new to science, namely: Sakaina glabra sp. nov. and Sakaina granulata sp. nov.; while three species are recorded for the first time from China: Pinnaxodes majorOrtmann, 1894, Pinnaxodes mutuensisSakai, 1939, and Sakaina japonicaSerène, 1964. Sakaina glabra can be easily distinguished from congeners by lacking a thick rim of pubescence along the anterolateral margin of the carapace. Sakaina granulata closely resembles S. asiatica (Sakai, 1933), but differs mainly in having a row of granule-like denticles along the anterolateral margin of its carapace. 相似文献
17.
Ana Ortega Olivencia Juan Antonio Devesa Alcaraz 《Plant Systematics and Evolution》1993,184(3-4):139-158
The genusScrophularia in the Iberian Peninsula and Balearic Islands comprises two sections,Scrophularia andCaninaG. Don. Analyses were carried out on flower production, flower duration and their sexual phases, pollen and nectar production together with observations on their pollinators. Nectar production is correlated with corolla size and pollen production with anther size. The taxa of sect.Scrophularia show greater nectar and pollen production than those of sect.Canina. Also, those of the first section produce more ovules per ovary than those of the second group, production being correlated with the ovary size.Some observations on floral and reproductive biology in some species ofScrophularia from the Iberian Peninsula and the Balearic Islands. I. 相似文献
18.
Three new species ofGalium from the NW. Himalaya in Pakistan are described and illustrated.Dedicated to Prof.K. H. Rechinger on the occasion of his 80th birthday. 相似文献
19.
Gobert Sylvie Defawe Olivier Lepoint Gilles Demoulin Vincent Bouquegneau Jean-Marie 《Hydrobiologia》2001,455(1-3):121-125
In Posidonia oceanica (L.) Delile, anthesis induces a decrease in the number of juvenile leaves resulting in a significant reduction in the number of leaves on the flowering shoots. All the leaves of the flowering shoots are narrower than the leaves of nonflowering shoots. A modification of the leaf growth also appears in flowering shoots: the oldest leaves are longer and the leaves induced during or after anthesis are shorter. At 10 m depth, in the Bay of Calvi, anthesis lasts roughly 3 months and the flowering is induced 7 months before anthesis. 相似文献
20.
Adaptive photosynthetic strategies of the Mediterranean maquis species according to their origin 总被引:2,自引:0,他引:2
In consideration of their origin the adaptive strategies of the evergreen species of the Mediterranean maquis were analysed. Rosmarinus officinalis L., Erica arborea L., and Erica multiflora L. had the lowest net photosynthetic rate (PN) in the favourable period [7.8±0.6 mol(CO2) m–2s–1, mean value], the highest PN decrease (on an average 86 % of the maximum) but the highest recovery capacity (>70 % of the maximum) at the first rainfall in September. Cistus incanus L. and Arbutus unedo L. had the highest PN during the favourable period [15.5±5.2 mol(CO2) m–2s–1, mean value], 79 % decrease during drought, and a lower recovery capacity (on an average 54 %). Quercus ilex L., Phillyrea latifolia L., and Pistacia lentiscus L. had an intermediate PN in the favourable period [9.2±1.3 mol(CO2) m–2s–1, mean value], a lower reduction during drought (on an average 63 %), and a range from 62 % (Q. ilex and P. latifolia) to 39 % (P. lentiscus) of recovery capacity. The Mediterranean species had higher decrease in PN and stomatal conductance during drought and a higher recovery capacity than the pre-Mediterranean species. Among the pre-Mediterranean species, P. latifoliahad the best adaptation to long drought periods also by its higher leaf mass per area (LMA) which lowered leaf temperature thus decreasing transpiration rate during drought. Moreover, its leaf longevity determined a more stable leaf biomass during the year. Among the Mediteranean species, R. officinalis was the best adapted species to short drought periods by its ability to rapidly recover. Nevertheless, R. officinalis had the lowest tolerance to high temperatures by its PN dropping below half its maximum value when leaf temperature was over 33.6°C. R. officinalismay be used as a bioindicator species of global change.This revised version was published online in March 2005 with corrections to the page numbers. 相似文献