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1.
New information on Aegires ortizi Templado, Luque & Ortea,1987 is given, and two new species of the genus Aegires aredescribed, one from the Caribbean and one from the MediterraneanSea. A key to the North Atlantic species of Aegires is given. (Received 10 February 1989; accepted 11 July 1989)  相似文献   

2.
Vertical distributions and diel migrations in the 0–1000m water column at a position in the Northwestern MediterraneanSea are given in detail for the main species of gelatinous macrozoo-plankton:three siphonophores (Abylopsis tetragona, Chelophyes appendiculataand Lensia conoidea), one hydromedusa (Solmissus albescens)and one pyrosomid (Pyrosoma atlanticum). Extensive diel verticalmigration occurred in these five species, particularly in A.tetragona,S.albescens and P.atlanticum for which the bulk of the populationmigrated as a compact unit. Pyrosoma atlanticum underwent thelargest migration, with a mean amplitude of 515 m. The migrationpattern of L.conoidea was more complex. Its day-distributionwas bimodal and at night part of the population ascended towardsthe surface, while the other part appeared to undergo a weakreverse migration of  相似文献   

3.
A new species of cephalaspidean gastropod from MediterraneanSea (West Naples Gulf, Italy) is described. This species, Haminaeafusari, is characterised mainly by the presence of short parapodiallobes, which cover only the anterolateral parts of the shell;the prostatic gland has two lobes separated by a narrow andcylindrical zone; the lateral teeth of the radula are all smooth;the penis has a triangular section at the apical zone and asmall sharpened tip; and the spawn is horse-shoe-shaped or coiledin a single spiral. This species is compared with all the Europeanspecies of the genus and a key to identification is provided. (Received 4 May 1992; accepted 4 January 1993)  相似文献   

4.
Photoinhibition of Seed Germination in Mediterranean Maritime Plants   总被引:4,自引:1,他引:3  
Photoinhibition of seed germination was shown for Allium staticiforme,Brassica tournefortii, Cakile maritima and Otanthus maritimus,all plant species inhabiting sandy coasts of the MediterraneanSea. Germination of A. staticiforme was found to be typicallyMediterranean in regard to its temperature range (>0–20°C), while B. tournefortii germinated optimally at intermediatetemperatures (15–25 °C). Light sensitivity was morepronounced in the latter species and 50 % inhibition of seedgermination was obtained with photon flux densities of approximately0.1 and 0.015 mol m–2 d–1 in A. staticiforme andB. tournefortii, respectively. However, the slopes of the regressionlines of germination plotted against the logarithm of whitelight flux density are similar in both species. From monthlyexperiments performed under fluctuating conditions of temperatureand light, simulating the elimate of Athens throughout the year,optimal germination response peaked in ‘winter’conditions for A. staticiforme, while a bimodal pattern wasobserved for B. tournefortii (maxima at the warm ends of therainy season). In contrast to the other plants, a fifth speciestested, Crithmum maritimum, showed an absolute light requirement,probably related to the rocky habitats of the species; the optimumgermination period coincided with the rainy season. Pot experimentswith seeds of the five species buried at various depths confirmedthat maximum emergence is favoured by shallow depths (0.5–1cm). It is concluded that seed germination in maritime plantsof the Mediterranean rim is mediated by a photoinhibition mechanismwhich can be considered an adaptation strategy against surfaceseedling establishment at the harsh, sandy or shingle, sea coasthabitats. Allium staticiforme, Brassica tournefortii, Cakile maritima, sea rocket, Crithmum maritimum, rock samphire, Otanthus maritimus, ton-weed, seed germination, light, photoinhibition, phytochrome, seedling emergence  相似文献   

5.
Vertical distributions at noon and midnight of copepodites,males and females of three coexisting species of freshwatercyclopoid copepods, Cyclops vicinus (a cold-water form), Thermocyclopscrassus and Mesocyclops leuckarti (warm-water forms), were studiedin Dreiangel Lake, a small eutrophic gravel pit. The largestspecies, C. vicinus, inhabits deep water layers, both at noonand midnight, while the smaller species, T.crassus and M.leuckarti,inhabit upper water layers. In all three species, copepoditesand males live closer to the water surface than females. Insummer, abundance of the smallest species (T.crassus) is highest,although finite birth rates are lowest. The distribution patternsand population characteristics suggest that the vertical distributionof cyclopoid copepods in Oreiangel Lake is mainly governed byfish predation; different temperature tolerances and preferencesof the three species may also be of significance.  相似文献   

6.
The abundance, frequency of dividing cells and growth ratesof the planktonic cyano bacteria Synechococcus sp. during thesummer of 1995 and 1996 were estimated in the Northwest MediterraneanSea to test whether depth-dependent growth rates of this speciesexplain its dominance in the deep chlorophyll maximum (DCM)layer formed during summer thermal stratification in the NWMediterranean, compared to the surface layer. Abundance at theDCM layer (50–70 m) was up to two orders of magnitudegreater than that at the surface, with values ranging from 1.7to 13x106 cells I-1 and from 4 to 175 x 106 cells I-1 at thesurface and in DCM waters, respectively. Gross growth rates,however, were much higher at the surface than in the DCM layer(surface: 0.76–1.07 day DCM: 0.30–0.47 day-1 Thehigher gross growth rates at the surface layer were supportedby a higher frequency of dividing cells (surface: 0.09–0.24;DCM: 0.01–0.12). The negative correlation between theabundance or standing stock and growth rates of these planktonicpicocyanobacteria points to losses, and not growth rate, asthe main control on the abundance of Synechococcus. Althoughwe provide some evidence that grazing alone may be able to accountfor these losses, further, direct determinations are clearlyneeded to elucidate the regulation of the abundance of Synechococcusin the NW Mediterranean.  相似文献   

7.
Vertical distributions and diel migrations of the main speciesof micronekton, four euphausiids, one mysid, one decapod andthree fishes, were described in detail in the 0–1000 mwater column on a fixed station in the Northwestern MediterraneanSea. The euphausiids Euphausia krohni and Thysanopoda aequalis,the decapod Gennadas elegans and, to a lesser extent, the fishArgyropelecus hemigymnus were shown to perform clear diel verticalmigrations. Results of horizontal hauls at a given depth aroundsunrise and sunset showed a marked diurnal symmetry of the migratorycycles, particularly for E.krohni, T.aequalis and G.elegans.The behaviour of the euphausiid Nematoscelis megalops was morecomplex: it presented a repetitive bimodal day distributionand only part of its population migrated. As very weak or non-migratorswe found the euphausiid Stylocheiron longicorne and the bathypelagicmysid Eucopia unguiculata, for which migration concerned onlysome of the older individuals. The fishes Cyclothone braueriand Cyclothone pygmaea appeared to be non-migrants. As depthincreased, C.braueri was replaced by C.pygmaea, with maximumconcentrations at 350–550 and 550–700 m depth, respectively.  相似文献   

8.
Simone Pouyet 《Geobios》1978,11(1):119-123
The genus Phoceana JULLIEN and CALVET was recorded only from the recent North Atlantic and the MediterraneanSea. We discovered a fossil species in the Lower Pliocene from southern Spain.  相似文献   

9.
中国菲寄蝇属分类研究(双翅目: 寄蝇科)   总被引:1,自引:0,他引:1  
赵建铭  陈小琳 《昆虫学报》2007,50(9):933-940
经研究发现中国菲寄蝇属现共有9种,其中包括4新种:金额菲寄蝇Phebellia aurifrons sp. nov.,褐粉菲寄蝇Ph. fulvipollinis sp. nov.,宽叶菲寄蝇Ph. latisurstyla sp. nov.和毛基节菲寄蝇Ph. setocoxa sp. nov.。我国新记录3种:叶蜂菲寄蝇Ph. clavellariae (Brauer & Bergenstamm),灰粉菲寄蝇Ph. glauca (Meigen)和拟灰粉菲寄蝇Ph. glaucoides Herting。本文除详细描述新种特征及绘制特征图外,还提供中国菲寄蝇属已知种类的分种检索表。  相似文献   

10.
中国的光肩星天牛类群   总被引:16,自引:0,他引:16  
吴蔚文  蒋书楠 《昆虫学报》1998,41(3):284-290
该文讨论我国光肩星天牛Anoplophoraglabrlpennis(Motschulsky)类群的外部形态和外生殖器的主要鉴别特征,寄主、地理分布、起源及其演化。光肩星天牛主要分布在山西吕梁山、太行山以东的广大平原地区,寄主广泛,主要有榆、复叶槭、杨、柳、五角枫等。黄斑星天牛主要分布在秦岭以北,山西吕粱山太行山以西的陕甘宁地区,向东已扩展到河南、河北;主要为害杨树,也为害柳、榆。四川星天牛主要分布于秦岭以南的西部地区,北限在陕西太白山到甘肃天水一带;主要为害柳。在秦岭以北到天水之间是黄斑星天牛和四川星天牛的重叠分布区,山西太行山两侧南北走向的狭长地带是光肩星天牛和黄肩星天牛重叠分布区,两个狭长地带交会处,大约在秦岭以北的陕西和(或)山西境内有三个种的重叠分布区域.在云、贵、川地区广泛分布着四川星天牛,至今还没有发现光肩星天牛、黄斑星天牛和蓝角星天牛,后者应该是一个值得怀疑的种。  相似文献   

11.
The type species of the genera Mysella Angas, 1877, RochefortiaVélain, 1878, Rochefortula Finlay, 1927 and AltenaeumSpaink, 1972 are illustrated and discussed. A new genus Kurtiellais introduced for ‘Mysellabidentata (Montagu,1803) and other European species currently placed in Mysella.These species display a unique diagnostic character state inhaving the cardinal platform deeply receding to house the internalligament, along with an array of more general montacutid traits.At the species level, diagnostic characters are given for thetype species K. bidentata, and for other included species K.ovata (Jeffreys, 1881), K. pellucida (Jeffreys, 1881), K. triangularis(Watson, 1897) and K. tumidula (Jeffreys, 1866), based mostlyon characters of the prodissoconch and on shell outline. Montacutasimillima Smith, 1892, from St Helena, is considered a juniorsynonym of K. pellucida. The loss of labial palps in K. tumidulais interpreted as a further derived character, which does notconflict with the generic placement in Kurtiella. (Received 28 August 2007; accepted 1 December 2007)  相似文献   

12.
A revision of the Recent species of the genus Goodallia (Astartidae)is presented. Adult shell and prodissoconch morphology of allthe species are described and figured. In total, five speciesare recognized: G. triangularis (Montagu, 1803), G. pusilla(Forbes, 1844), G. macandrewi (Smith, 1881), G. micalii new species,and G. gofasi new species. G. triangularis and G. pusilla are widespreaddistributed in the Atlantic coasts of Europe and North Africa,and in the Mediterranean. G. macandrewi is restricted to thetype locality in the Canary Islands, while what has been calledG. macandrewi from the Mediterranean corresponds to an undescribedspecies here named G. micalii, distributed in the Central andEastern Mediterranean. A second undescribed species from offthe Atlantic Moroccan coast is named G. gofasi, and is knownonly from the type material of station B33 of the expedition CINECA CHARCOT III. The named forms, variability and distributionof G. triangularis are discussed. (Received 30 January 1998; accepted 27 August 1998)  相似文献   

13.
Among diverse marine invertebrate taxa, the evolution of a non-planktotrophiclarva is often associated with increased rates of cladogenesis,compared to related taxa that retain the ancestral planktotrophiclarval form. Molecular phylogenetic analyses of non-planktotrophic(and, presumably species-rich) clades of marine invertebratesare rare. Here we analyze 1542 base pairs of mitochondrial DNAsequence comprising two gene regions, the cytochrome oxidaseI gene and the putative control region and flanking sequences,for 23 molecular lineages in the obligately brood-protectingasteroid genus Leptasterias. Using maximum likelihood, minimumevolution, and maximum parsimony methods, five major cladeswere identified that corresponded to five taxa (species or speciescomplexes) in the subgenus Hexasterias, section camtschatica(following the taxonomy of Walter K. Fisher). Two clades (L.aequalis> complex and L. aleutica/L. camtschatica complex) werecomposed of numerous molecular lineages (7–8 lineages/clade),and several clades had multiple shallow nodes, suggestive ofrecent radiations. Two of the clades (L. aleutica/L. camtschaticacomplex and L. hexactis complex), with geographic ranges restrictedto latitudes higher than 48°N, were lacking deep phylogeneticnodes. This pattern is consistent with the hypothesis that high-latitudetaxa have high rates of extinction due to repeated climaticcrises. A log-likelihood ratio test performed on the camtschaticasection, including a member (Leptasterias polaris) of the polarissection and using a representative (L. mülleri) of Leptasteriassubgenus Leptasterias as an outgroup, demonstrated that thecamtschatica section is monophyletic.  相似文献   

14.
Digestive enzymes of copepodite V (CV) Calanus finmarchicusand C.hyperboreus from two different depths were compared duringMIZEX 1984 (June/July) at stations in the ice and open water.CV of both species from 500–200 m showed reduced enzymeactivity, indicating that they were in a resting stage. In moultingexperiments at the end of June using CV from 100–0 m moultingwas delayed and began only after 3 weeks in C.finmarchicus andafter 3 months in C.hyperboreus. These results suggest thatthe deep CV populations are the seed of the new overwinteringstock. In surface CV C.finmarchicus and C. hyperboreus enzymeactivities were generally much higher than in deep CV. In neitherspecies were enzyme activities correlated with chlorophyll concentrations.Activities in C.finmarchicus reflected overall phytoplanktondistribution and were highest in the marginal ice zone, whereasthey decreased under the ice except for polynya stations onthe East Greenland Shelf. In surface C.hyperboreus digestiveenzymes were not correlated with those of C.finmarchicus, pointingto different diets or regulatory mechanisms. Enzyme activitywas lowest in the marginal ice zone and increased under theice. High activities were found at polynya stations and otherclose pack ice. The utilization of ice algae by C.hyperboreuscould explain these discrepancies in digestive enzyme activitiesof both species.  相似文献   

15.
Nuclei were isolated from cotyledons of a range of accessionsfrom 14 species of Glycine. These were stained with ethidiumbromide and the relative fluorescence for each genotype wasmeasured by flow cytometry. The DNA content was estimated bycomparison of relative fluorescence with that from nuclei fromseedling leaves of Allium cepa, whose DNA content has been calculatedpreviously by chemical assay. The 4C amounts for diploid Glycineranged from 3.80 to 6.59 pg. Two groups of diploid species appearedfrom the analysis. The first consisted of species with amountsranging from 3.80 to 5.16 pg and included G. canescens (AA),G. argyrea (A1 A1), G. clandestina (A2A2), G. microphylla(BB),G. latifolia (B1B1), G. tabacina 2n=40 (B2B2), G. tomentella2n=38 (EE) and 2n=40 (DD), G. max and G. soja (GG), G. arenariaand G. latrobeana. A second group had higher DNA contents rangingfrom 5.27 to 6.59 pg, and consisted of G. curvata, G. cyrtoloba(CC), and G. falcata (FF). The polyploid species, G. tabacina2n=80 (AABB, BBB1B1), G. tomentella 2n=78 and 2n=80 (AAEE andDDEE, respectively) contained amounts approximating to the sumsof the respective parental diploid species thought to have givenrise to these allotetraploids. Intraspecific variation was detectedin the DNA content of G. canescens. Within the overall distributionof DNA amounts found in A genome species, each genome containeda range of DNA contents specific to that species. This phenomenonwas also detected amongst B genome species.  相似文献   

16.
Three species of loricate choanoflagellates (Choanoflagdlida,Acanthoecidae), collected from the Andaman Sea near Phuket Island(SW Thailand), have been described and referred to Apheloeciongen.nov. (holotype: A. quadrispinum sp.nov.). All species possessa single-chambered lorica composed of one transverse costs overlaidby a limited number of longitudinal costae which converge posteriorly.Anteriorly the longitudinal costae protrude above the transversecosta as sharp pointed spines. In A. quadrispinum sp.nov. andA. pentacanthum sp.nov. the lorica is terminated by a shortposterior spine, whereas in A. articulatum sp.nov. the pedicelis much more prominent, consisting of several costal stripswhich are joined end-to-end. The species of Apheloecion appearto be most closely related to species of Calliacantha and Monocosta.None of the species described are so far known from localitiesoutside the Andaman Sea.  相似文献   

17.
THOMAS  HENRY 《Annals of botany》1986,57(2):211-223
Cocksfoot (Dactylis glomerata L.). perennial ryegrass (Loliumperenne L.) and Italian ryegrass (L. multiflorum Lam.) plantswere grown on deep (75–95 cm) columns of soil in glasshousesand growth rooms with and without irrigation. The species inwhich growth declined least rapidly after water had been withheldwere those which transpired most slowly. During early establishmentin the glasshouse cocksfoot transpired least because of slowroot growth. In the growth room, when root systems were deeperand denser, perennial ryegrass transpired least because of lowleaf water conductance. Results are discussed in relation to(a) drought resistance in the three species; (b) breeding forincreased drought resistance through modifying root distributionand leaf water conductance; and (c) the use of isolated soilcolumns in water relations studies. Dactylis glomerata L., Lolium perenne L., Lolium multiflorum Lam., cocksfoot, perennial ryegrass, Italian ryegrass, transpiration, roots, leaf water conductance  相似文献   

18.
RAO  P. B. 《Annals of botany》1988,61(4):531-540
Quercus floribunda Lindl. (tilonj oak), a late successionalspecies, and Cupressus torulosa D. Don. (surai), an early successionalspecies, were compared in terms of seed germination and seedlinggrowth. In Petri dish germination tests in which light quality,temperature and osmotic water stress were varied, the germinationof both species was reduced by continuous dark or far-red lightand by osmotic water stress. These effects were greater on thegermination of surai than on that of tilonj oak. The growthof seedlings in soil was measured over a twelve-month periodduring which different levels of shading and different wateringregimes were applied. Surai was less affected than tilonj oakby reduced soil moisture, but the effect of deep shade treatmentswas greater on surai than with tilonj oak. At higher soil moisturestress seedlings of surai attained greater height then tilonjoak, but the latter achieved higher dry weight and a higherroot: shoot and lower leaf-weight ratio. Quercus floribunda Lindl. (tilonj oak), Cupressus torulosa D. Don. (surai), seed germination, seedling growth, environmental factors, regeneration  相似文献   

19.
The phytoplankton species in the North Pacific central environmentare known to be distributed into two vertically distinct assemblagesduring most of the year. Key species are defined for each assemblage.The vertical distributions of these key species indicate thatthe increase in abundance of deep species closely parallelsthe increase in chlorophyll a at the top of the chlorophyllmaximum layer. The chlorophyll maximum is comprised of speciescharacteristic of the deep assemblage, with only insignificantnumbers of shallow species.  相似文献   

20.
Phylogenetic analyses of nucleotide and amino acid sequencesof the chloroplast protein coding generps4 were performed for225 species of mosses, representing 84% of families recognizedby Vitt (1984. In: Schuster RM, ed. New manual of bryology,vol 2. Nichinan: Hattori Botanical Laboratory), under the criterionof maximum parsimony with Takakia and Sphagnum as outgroups.Most parsimonious topologies converge to a scenario whereinthe Andreaeidae are monophyletic and sister to the Bryidae (peristomatemosses), the Nematodonteae and the Buxbaumiaceae form a monophyleticlineage, the Diphysciaceae are sister to the Arthrodonteae and,within the latter, the Funarineae-Encalyptineae-Timmiaceae-Haplolepideaecompose a monophyletic clade sister to remaining diplolepideousmosses. This hypothesis suggests that early in the evolutionof the Arthrodonteae, two major lineages diverged, with oppositeand alternate peristomes, respectively. Bootstrap support forthe deep dichotomies is poor or lacking but increases when proteintranslations ofrps 4 sequences are included in the analysis.Several novel systematic hypotheses are raised, including (a)a diplolepideous rather than haplolepideous origin of the Pleurophascaceae;(b) an affinity of the Catascopiaceae with the Funariineae ratherthan the Bryineae; and (c) a close relationship of the Calomniaceaeand Mitteniaceae to the Rhizgoniaceae. The advantages and disadvantagesof a single gene phylogeny are discussed with respect to theidentification of polyphyletic familial or suprafamilial taxa.Copyright 2001 Annals of Botany Company Bryophyta, mosses, phylogeny, rps4, evolution, peristome, parsimony, sequences  相似文献   

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