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1.
During ongoing DNA barcode (COI‐5P) surveys of the macroalgal flora along the northwest Atlantic coast, we discovered a population of Ceramium secundatum in Narragansett Bay, Rhode Island, USA. This species is regarded as common and widespread in the northeast Atlantic, ranging from Norway to Morocco, but until now has not been reported from the western Atlantic. Several lines of evidence suggest that C. secundatum may be introduced to Narragansett Bay: (1) despite extensive collecting, specimens have only been obtained from a limited geographic range in the northwest Atlantic; (2) three other nonindigenous seaweed species are reportedly introduced in this region, which is thought to be a consequence of shipping; and (3) this species is introduced to South Africa and New Zealand. To investigate this suspected introduction, we applied population genetic analyses (using the cox2‐3 spacer) to compare the Narragansett Bay C. secundatum population to native populations in the Republic of Ireland and the United Kingdom. Collectively, analyses of biogeographical and molecular data indicate that C. secundatum is likely introduced to Narragansett Bay. The implications of this discovery are discussed.  相似文献   

2.
A detailed account of female reproductive features ofPlumariella yoshikawae is presented.Plumariella yoshikawae is recognized as morphologically similar toDelesseriopsis elegans in several features, particularly in the sequence of branch initiation, the presence of gland cells on the abaxial sides of the basal segments of the lateral branches, having carpogonial branches on the basal segments of unmodified lateral branches, and the maturation of the carposporophyte at well below the thallus apices. These features indicate thatPlumariella yoshikawae is best removed from the Ptiloteae and is correctly placed in the tribe Delesseriopsideae. The generaPlumariella andBalliella are retained along withDelesseriopsis within the tribe Delesseriopsideae.  相似文献   

3.
Four flattened Gracilaria species have been reported from Taiwan: G. spinulosa, G. vieillardii, G. textorii and G. punctata, identified based on branching pattern, the presence or absence of spines, and characters that often vary seasonally. Gracilaria spinulosa was originally described from the type locality, Tainan. Species with toothed margins are usually referred to G. “vieillardii”; those with smooth margins to G. “textorii”, and those with smooth margins and dark spots scattered over the blade to G. “punctata”. Molecular analyses show that specimens with marginal teeth cluster in three different groups: a G. “vieillardii” clade, a G. spinulosa clade, and a clade sister to G. spinulosa. An undescribed species comprises the third clade, which is distinguished by its relatively large gonimoblast cells and weakly developed tubular nutritive cells. The three clades can be separated by the character of the tubular nutritive cells, the size of gonimoblast cells and certain vegetative features. Plants with entire margins form a single clade characterized by cystocarps with basal tubular nutritive cells and their absence in the cystocarp cavity. They are nested in the Hydropuntia complex and are referred to as Gracilaria “punctata” here. The records of G. textorii and G. punctata from Taiwan require reinvestigation in comparison with the Japanese species.  相似文献   

4.
The taxonomic placement of four antarctic species of the marine red algal family Phyllophoraceae (Gigartinales) is assessed within a preliminary molecular phylogeny of the family based on direct sequence analysis of the chloroplast gene rbcL. Parsimony analysis of rbcL sequences indicates that Gymnogongrus antarcticus and Gymnogongrus turquetii cluster in a clade consisting predominantly of southern hemisphere species currently placed in Gymnogongrus and Ahnfeltiopsis, whereas Phyllophora ahnfeltioides and Phyllophora antarctica cluster in a separate clade that is widely divergent from the northern hemisphere Phyllophora clade. Results from molecular and morphological data challenge the current taxonomic concept that type of life history is a phylogenetically valid criterion for recognition of genera in the Phyllophoraceae.  相似文献   

5.
Yeon-Shim  Keum  Lee  In Kyu 《Hydrobiologia》1993,260(1):97-104
The vegetative and reproductive morphology of two epiphytic Herpochondria species, H. corallinae (Martens) Falkenberg (the type species) and H. elegans (Okamura) Itono from Korea were investigated. They are bilaterally compressed and alternate-distichously branched, and lateral branches are produced by oblique divisions of the apical cell. Procarps are restricted to the first periaxial cell of the branches. Spermatangial mother cells produce one or two spermatangia. H. corallinae forms tetrasporangia on six periaxial cells, whereas H. elegans has them on only the two lateral periaxial cells. The prostrate habit, the production of six periaxial cells in opposite pairs, and tetrasporangial stichidia are confirmed as diagnostic characters of the genus Herpochondria.  相似文献   

6.
Common problems faced in farming of the red algal genus Kappaphycus/Eucheuma are “ice-ice disease” and the occurrence of epiphytes. Considerable work has been documented on “ice-ice disease” and it's mode of infection but limited information is available on the emergence of epiphytes. The present study addresses the phenomenon of epiphyte infection, its prevalence in commercially cultivated red alga, Kappaphycus alvarezii, and their variability associated with seasonality. Cultured seaweed became susceptible to epiphytes in the dry seasons (1) between March – June and (2) September – November. Findings revealed Neosiphonia savatieri (Hariot) M. S. Kim et I. K. Lee, as the dominant infecting epiphyte, representing up to 80–85% of the epiphyte present during peak seasons. Besides N. savatieri, Neosiphonia apiculata, Ceramium sp., Acanthophora sp. and Centroceras sp. were observed in smaller quantities. SEM (Scanning Electron Microscope) micrographs revealed the epiphyte's attachment to the host. Further histological study showed the extent of penetration of epiphytes into the host's cortex tissues and condition of its surrounding tissues. The outbreak of epiphytic filamentous red algae also correlated with drastic changes in seawater temperature and salinity during March– June and September – November.  相似文献   

7.
Developmental patterns in four species of Ceramiaceae were determined using excised thallus apices grown under a range of light periods. Models of thallus development and organization based on these patterns are presented. Increased rates of apical cell division, greater growth of apical fragments and increased average cell size were found with increasing number of hours light per day between 8–16 and 16–8 h. No aspect of growth investigated was associated with photoperiodic phenomena, and growth occuring during the light break (8-7.5-1-7.5 h) was intermediate between that in 8–16 and 12–12 h. Three patterns of cell elongation were found in the four species in which (1) cell age, (2) cell age and position and (3) cell age, cell position and light period determined cell length at different axial cell positions. Elongation was followed within cells, along axes ofAntithamnion spirographidis for plants grown under different day lengths. Three regions of development were found along main axes: (1) an apical region in which basipetal expansion was greater than acropetal expansion. (2) a zone of stability with equal elongation in apical and basal growth region of cells, and (3) a basal region with greater acropetal expansion. With increasing daylength, the zone of stability was extended to greater ranges of cell length.  相似文献   

8.
Xia  Bang-Mei  Tseng  C.K.  Wang  Yong-Qiang 《Hydrobiologia》2004,528(1-3):201-207
A previously unknown species of anostracan is presented and described herein as Eubranchipus stegosusn. sp. This species is unique in that the male bears large, sub-quadrate, transverse, dorsal thoracic projections. Eubranchipus stegosus n. sp. is most closely related to E. moorei and E. holmani and may be endemic to southwestern Georgia. However, anostracans are poorly sampled throughout the southeastern United States, and additional surveys should be conducted to better understand this species' distribution and degree of rarity.  相似文献   

9.
Aspergillus taichungensis isolated from a soil sample collected in Taiwan is described as a new species. The new species is characterized by its restricted growth on Czapek's and malt extract agars and its white to light yellow colonies, radiate conidial heads, smooth and often diminutive conidiophores, hemispherical to elongate vesicles with biseriate aspergilla (conidiogenous cells), globose, micro-verrucose conidia and dark brown sclerotia. The species somewhat resemblesA. versicolor, A. terreus andA. flavipes, but differs in cultural and morphological details, and is considered to represent an interface species in the subgenusNidulantes.  相似文献   

10.
Studies on the seasonality of 5Gracilaria species (G. corticata, G. crassa, G. millardetii, G. salicornia, G. verrucosa) were carried out. The seasonal abundance of the various species varied with time and geographical location. Nevertheless, a general single peak was evident between the months of September and December.G. verrucosa on the other hand had its peak biomass in July/August.G. millardetti is the only species which apparently preferred lower salinities; the rest of the species had no special trends as far as salinity is concerned. The occurrence ofG. verrucosa for a very short period during the cool part of the year is attributed to the high temperature that prevails in the coastal waters.  相似文献   

11.
The genus Reinboldiella essentially consists of tiny, membranous blades, epiphytic on benthic red algae, with a wide distribution in the north-western Pacific Ocean (Taiwan, Korea and Japan). In this study, we re-examined the generitype R. schmitziana from Taiwan and neighbouring islands. Two new species of Reinboldiella, R. orientalis sp. nov. and R. taiwanensis sp. nov. are recognized from Taiwan based on comparative morphological studies and molecular analyses of RuBisCO large subunit (rbcL) gene sequences. Reinboldiella orientalis is characterized by its rosette-like appearance, with both erect and prostrate, membranous flat blades whereas R. taiwanensis is distinguishable by mainly consisting of erect, membranous blades with few, short prostrate blades in basal parts of the thalli. Thalli of R. schmitziana also have a rosette-like appearance, but their erect flat blades have cylindrical bases or stipes. The rbcL phylogenetic analyses also support the separation of R.schmitziana’ from Taiwan and R. schmitziana from Japan and Korea.  相似文献   

12.
Molina  Ximena  Montecino  Vivian 《Hydrobiologia》1996,326(1):415-420
Photoautotrophs can cope with an increase in ultraviolet (UV) irradiance in the aquatic environment, through protection and acclimation mechanisms (i.e. synthesis of UV-absorbing compounds). This capacity has been proven to vary according to the organism's sensitivity. To quantify variations of this capacity between the different parts of macroalgae, an in vitro study was performed with the tips, cystocarps and thalli segments of Gracilaria chilensis. Whole algae incubated during 3 days at high and low PAR, supplying UV B (4.6 µW cm–2) during 2 hours showed, as predicted, an increase in absorption (OD) at 320 nm of the different parts, after the first day of exposure to UV B. The tips presented the highest increase in the standardized OD at 320 nm relative to cystocarps and thalli segments; their mean percentage of increase was 38% and 29% at low and high PAR, respectively. The lowest sensitivity was consistently found in the thalli segments, while the highest was in the tips. The tips are important for growth and therefore they play a major role in the maintenance of the Gracilaria populations. Acclimation mechanisms that occurred in a short time scale, and mainly in the tips, may allow Gracilaria to have an almost immediate protection to increases in UV B fluxes.  相似文献   

13.
New Zealand populations of Gracilaria chilensis are uniform in anatomical reproductive characteristics but vary morphologically and have been found to separate into two distinct groups with respect to agar methylation level, namely low (24–30%) and high (43–47%). To investigate the genetic variation within New Zealand populations of this species, 14 isozyme loci detected by starch-gel electrophoresis were examined in 17 wild populations from a wide range of localities, and in cultures derived from these populations. Five of these loci were polymorphic, but the genetic variation within populations was low: of the 17 populations examined, 15 were fixed at all loci (heterozygosity 0.000) and in the remaining two populations the observed heterozygosity was still low (0.004 and 0.011). The genetic distances between the populations ranged from 0.00 to 0.43. UPGMA cluster analysis separated the populations into two groups, a northern group and a group found throughout the country. Although these two groups do not correlate with the two groups based on agar methylation level at every locality, the correlation is sufficiently striking to merit further investigation.  相似文献   

14.
Azanza-Corrales  R.  Sa-a  P. 《Hydrobiologia》1990,204(1):521-525
Six cultured strains of Eucheuma denticulatum and E. alvarezii, from which stocks can be selected for the development of a Eucheuma seedling bank, were tested for their carrageenan quality from June to November 1988. Percent yield of all the varieties taken together was apparently higher in June, becoming lower in November (regression, r –0.785, probability, p 0.001). Stepwise regression analysis was done to determine the existence of any relationship between any of the following parameters: gel strength, viscosity, sulfate content, month of sampling, and yield, whether taken individually or in combination. Results show variations of the yield with the month of sampling. ANOVA was performed to test whether there are differences in sulfate levels, gel strength, and viscosity between the Eucheuma alvarezii morphotypes. There was no significant difference between the green and the brown types.  相似文献   

15.
Matsuhiro  Betty  Urzúa  Carlos C. 《Hydrobiologia》1996,326(1):491-495
Palmaria decipiens, one of the most abundant red seaweeds of the chilean Antarctic, was collected in King George Island. The hot water extract (26% yield) showed by acid hydrolysis to contain xylose, galactose and traces of glucose. Fractionation with cetrimide gave a soluble neutral xylan and an insoluble fraction. The insoluble fraction afforded an acidic polysaccharide that contained 4.8% of uronic acids, 2.8% of sulfate and 18.9% of protein. Polyacrylamide gel electrophoresis showed that it was homogeneous. The GLC and HPLC analysis of the total acidic hydrolysis products showed that the acidic polysaccharide was composed of the neutral sugars galactose and xylose in the molar ratio 8.2:1.0 and of galacturonic and glucuronic acid in the ratio 1.5:1.0. The second-derivative FT-IR spectrum showed the characteristic amide I, II and III bands of proteins. Alkaline cleavage with 0.1 M NaOH indicated the presence of a glycoprotein with O-glycosidic linkage.Results found in this work suggest that the acidic polysaccharide extracted from Palmaria decipiens is an acidic xylogalactan-protein complex.  相似文献   

16.
A new species ofNeosartorya, N. multiplicata (anam.Aspergillus multiplicatus), isolated from soil collected at Houli, Taichung, in Taiwan, is described and illustrated. The species is characterized by its restricted growth on Czapek agar, white ascomata, nearly globose ascospores with ribbed surface ornamentation of several linear ridges, and a limited development of conidia on common media. A key to all accepted species of the genus is provided.  相似文献   

17.
Parker  Terry  McLachlan  J. 《Hydrobiologia》1990,(1):247-251
Field observations in sublittoral Prince Edward Island, Canada, indicated that on a friable sandstone substratum Chondrus crispus was more commonly associated with Phymatolithon sp. than with bare rock. Thus, a substantial proportion of the population of Irish moss along the coast of Prince Edward Island occurs on this encrusting coralline. These observation may be explained on the basis of the relative stability of the substratum in contrast to other studies in which sloughing of epithallial cells by species of both Phymatolithon and Lithothamnium has been reported to limit epiphytism by fleshy macrophytes.Issued as NRCC 31426.  相似文献   

18.
Craigie  James S.  Correa  Juan A. 《Hydrobiologia》1996,326(1):97-104
The appearance of cavities and holes in fronds of commercially cultivated Chondrus crispus is described. These ultimately arise from the ravages of a green spot or green rot disease system in which several biotic agents can participate. Nematodes capable of bacterial grazing were recovered from necrotic lesions and we suggest that the nematodes can facilitate wound healing in diseased tissues. Bacteria isolated from disease lesions and from the surfaces of healthy fronds were screened for pathogenic strains. A particularly virulent one, the DOR isolate, was purified from small dark orange colored colonies grown on dilution plates. It was present in necrotic tissue and also recovered from surface scrapings of old healthy fronds, but not from their apical regions. Growth of the DOR isolate appeared to be inhibited by other bacteria colonizing the algal surface. It was shown to be a facultative pathogen, the virulence of which depended on the availability of ammonium or constituents easily metabolized to ammonium. It induced green rot disease in healthy C. crispus and was recoverable in pathogenic form from experimentally infected frond apices. A wound, disease and recovery cycle is discussed to illustrate potential interrelationships involving animal grazers, algal endophytes, Petersenia pollagaster, bacteria and nematodes.  相似文献   

19.
The pore-systems of 17 extant species of Loxoconcha around Japan were studied in order to understand their phylogeny and evolution. The phylogeny was estimated by two steps. First, the 17 species were divided into two groups, Group A (12 species) and Group B (five species) by Pore pattern Below Eye tubercle (PBE) analysis. Then, intragroup relationships were estimated by Differentiation of Distributional pattern of Pore-system (DDP) analysis. PBE analysis reveals that species of Groups A and B have on average different ecological preferences. Species of Group A, which appeared in the late Pliocene, are more diverse, have both phytal and bottom-dwelling modes of life, possess fewer pore-systems in the ventral area, and inhabit normal marine environments. Species of Group B, whose oldest fossil record is the lower Miocene, are less diverse, have only bottom-dwelling species, possess more pore-systems in the ventral area, and tend to inhabit brackish water environments. The results of this study suggest that the differences in ecology may have had an impact on the late Cenozoic diversification around Japan. The primary invasion of Group B occurred before the lower Miocene,with no subsequent diversification. Group A invaded after the late Pliocene and immediately diversified, which created the present abundance of Loxoconcha species around Japan in both species diversity and variety of modes of life.  相似文献   

20.
Two new species ofTalaromyces, isolated from soils in Taiwan and Japan, are described and illustrated.Talaromyces eburneus, associated with aGeosmithia anamorph, is characterized by off-white colony on oatmeal agar, small pale yellow ascomata, and subglobose to ovoid ascospores with a smooth wall.Talaromyces muroii is characterized by restricted growth on Czapek agar, luteous ascomata, which are initiated by paired gametangia like those seen in members of the seriesFlavi, ellipsoidal and nearly smooth ascospores, and the absence of an anamorph.  相似文献   

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