bluuebunny/crossref_metadata_2025_split huggingface dataset:
RELATION OF TEMPERATURE TO DEVELOPMENT OF THE MACROTHALLUS OF DESMOTRICHUM UNDULATUM1,2
Authors: Rhodes Russell G. 
Published: April 2006

SUMMARY Desmotrichum undulatum (J. Agardh) Reinke (Phaeophyta) was found in the winter months in the littoral zone of a tidal marsh in Virginia. When field collections were maintained in culture media at 21 C, most cells of the thallus developed into plurilocular sporangia. Released zoospores developed into microthalli from which clonal cultures were established. At 21 C microthalli produced sporangia which released zoospores, subsequently developing into more microthalli. However, microthalli at 6 C formed filaments which subsequently developed into thalloid plants. When the thalloid plants of Desmotrichum formed in culture were subjected to 21 C, plurilocular sporangia were formed. These results support the proposition that the seasonal periodicity of Desmotrichum is due to a temperature‐regulated phenomenon in the development of macrothalli.
CONCENTRATION OF 85STRONTIUM AND 137CESIUM FROM WATER SOLUTIONS BY CLADOPHORA AND PITHOPHORA1
Authors: Williams Louis G. 
Published: April 2006

SUMMARYMajor differences were found among living algae, saprophytic ecosystems, nonliving algae, and other organic materials in their ability to concentrate 85strontium and 137cesium from water solutions of different Ca/K ratios and quantities available from batch and flowthrough cultures. As expected, live algae, greatly concentrate these radionuclides. The concentration factors of nonliving organic materials were much lower and varied with the material, not with the Ca/K ratio. The effect of high Ca++ and high K+ was to lower the uptake of cesium more than strontium.
TAXONOMY OF CHARA BRAUNII: AN EXPERIMENTAL APPROACH1
Authors: Proctor Vernon W. 
Published: April 2006

SUMMARYResults from the present study suggest that Chara braunii encompasses a complex of geographical races or incipient species that although morphologically similar, are isolated to varying degrees ranging from partial interfertility to complete reproductive incompatibility. Most of the 6 clones studied were interfertile to the extent that fertilization was followed by the development of black oospores, but subsequent germination tests disclosed that many of these either failed to germinate or gave rise to offspring that were partially or completely sterile. No support was encountered for the suggestion that C. braunii is of recent development or that it has been distributed rapidly throughout the world.
AUTECOLOGICAL STUDIES ON THE MARINE DIATOM RHIZOSOLENIA FRAGILISSIMA BERGON. I. THE INFLUENCE OF LIGHT, TEMPERATURE, AND SALINITY1
Authors: Ignatiades Lydia , Smayda Theodore J. 
Published: April 2006

SUMMARYThe influence of 113 combinations of temperature (9, 12, 18, 25, 30 C), salinity (5–35 ‰ at 5 ‰ intervals), and light (4 levels) on the mean daily cell division rate (K) of the Narragansett Bay clone of Rhizosolenia fragilissima was examined following appropriate preconditioning. Growth did not occur below 9 C, but was excellent (K =∼1.2) under certain combinations of light and salinity at 12, 18, and 25 C. The optimal salinity of 20–25 ‰ was temperature independent. Growth was not measurable at 5 ‰, although survival occurred. At 20 ‰ and 1200 ft‐c, K increased approximately 1.8‐fold from 0.65 to ∼1.2 between 9 and 18–25 C.The optimal light intensity was generally 600 ft‐c, although several light‐temperature‐salinity trends were found. At 10 ‰ at all temperatures, the mean daily division rate decreased with increasing light above 600 ft‐c, a response found at all salinities at 12 C, but not at other temperatures. Between 15 and 25 ‰, at 18 and 25 C, mean growth was independent of light intensity; at 30–35 ‰ a direct relationship with light may be present with maximum growth occurring at 1200–1800 ft‐c.The in situ and in vitro responses of Rhiz. fragilissima to salinity and the optimum and upper temperature levels are in general agreement. However, growth failure below 9 C in vitro is at odds with reports that natural populations occur even at −1.11 C. The questions of to what extent this discrepancy reflects the occurrence of thermal clones, different taxa, and/or experimental artifacts are briefly discussed. It is suggested that naturally occurring populations found below 9 C might be designated as Rhiz. fragilissima f. faeröensis, and that Rhiz. fragilissima f. bergonii be used for populations growing at higher temperatures, until this matter is resolved.Observations on auxospore formation are presented.
AUTECOLOGICAL STUDIES ON THE MARINE DIATOM RHIZOSOLENIA FRAGILISSIMA BERGON. II. ENRICHMENT AND DARK VIABILITY EXPERIMENTS1
Authors: Ignatiades Lydia , Smayda Theodore J. 
Published: April 2006

SUMMARYNutrient enrichment experiments were conducted with a Narragansett Bay clone of Rhizosolenia fragilissima to examine the potential influence of nutrients in regulating its seasonal cycle in this embayment, and their contribution to its coastal tendencies. Growth rates were measured at 18 C and 1000 ft‐c continuous illumination in surface waters enriched in 15 different ways. Narragansett Bay was sampled in March, May, September, and December. Six stations on a transect from this Bay to the Sargasso Sea were sampled during late summer.The data and our previous autecological observations are consistent with the idea that the annual cycle of this species in Narragansett Bay is associated with temperature, chemical “water quality,” and unknown factors. Its absence during late fall and winter may reflect low temperatures and a trace metal (Co, Mo) inadequacy. In early spring, low temperature appears to be the limiting factor, whereas in late spring and early summer trace metals again appear to prevent active growth. A late summer‐early autumn bloom occurs periodically during optimal temperature conditions; this can terminate independently of grazing pressure, and in spite of seemingly adequate light‐temperature‐salinity and phosphate conditions.
REPRODUCTION AND SYSTEMATICS OF THE MARINE ALGA DERBESIA (CHLOROPHYCEAE) IN NEW ENGLAND1,2
Authors: Sears J. R. , Wilce R. T. 
Published: April 2006

SUMMARYThe morphology, gross cytology, reproduction, and habitat ecology are described for Derbesia marina based on observations of New England field populations and laboratory cultures of this plant. These data, and additional observations on cultures of several other species of Derbesia from elsewhere and on type and other important collections, have been used to evaluate the systematic relationship of New England Derbesia with other species of this genus. The single Derbesia species in New England is referred to D. marina. The systematic criteria previously used to distinguish species within Derbesia are reviewed and interpreted within the context of the present investigation. In systematic studies, we stress the importance of the use of sporangial and chloroplast morphology, the presence or absence of pyrenoids, and reproductive history.Two types of life history are reported for D. marina in New England: (1) A form of D. marina collected at 20 m reproduces directly with stephanokontous zoospores growing into sporophytic plants of Derbesia morphologically identical to their parent thalli. (2) On the other hand, at least some New England, populations of D. marina have retained the genetic potential for producing a sexual generation (Halicystis ovalis), even though the latter is unknown for the coast of northeastern North America.3 Gametophytes (H. ovalis) were produced directly from enlargement and subsequent differentiation of uncleaved lateral sporangia in 2 cultured populations of New England D. marina. A single female and numerous male vesicles formed in this manner produced gametes, but neither fertilization nor parthenogenesis occurred; thus the entire life history was not completed in culture.The occurrence of the directly reproducing deep water form of D. marina is presented as evidence for speciation of a sporophyte (Derbesia) independent of its alternate gametophyte (Halicystis). An hypothesis is advanced to explain the source and means for expression of genetic variability necessary for speciation in a population of nonsexually reproducing Derbesia.
NUTRITIONAL STUDIES OF TWO RED ALGAE. I. GROWT RATE AS A FUNCTION OF NITROGEN SOURCE AND CONCENTRATION1
Authors: DeBoer James A. , Guigli Harry J. , Israel Thomas L. , D'Elia Christopher F. 
Published: April 2006

ABSTRACTGracilaria foliifera (Forsskal) Borgesen and Neoagardhiella bailiyi (Harvey ex Kiitzing) Wynne & Taylor were grown in continuous‐flow culture under controlled environmental conditions in 15 liter experimental chambers. Growth rate was related to the source and concentration of nitrogen enrichment supplied to the plants, Growth rate appeared to follow saturation‐type nutrient uptake kinetics for plants receiving ammonium, nitrate, urea of sewage effluent enrichments. Ammonium enrichment produced higher growth rates than nitrate of sewage enrichment. The lowest growth rates occurred in the chambers receiving unenriched seawater or urea. The low estimated constants (K) for growth were in the range of 0.2–0.4 (M N for all N enrichments examined. The low estimated values of K compare closely with those found for microalgae and indicate that both species possess the ability to utilize very low concentrations of N.
PRODUCTION OF EPIBENTHIC DIATOMS IN A SOUTHERN CALLIPORNIA IMPOUNDED ESTUARY1, 2
Authors: Riznyk Raymond Z. , Edens Jefferey I. , Libby Robin C. 
Published: April 2006

ABSTRACTIn situ epibenthic diatom productio was determined for four sites within Bolsa Bay (Orange Coutry), California, to assess the effect of estuative impoundment by a tidal gate. Mean annual values of 26 and 41 mg C m−2 h−1 were found in the finner sediment of the outer bay whereas mean annual values of 41 and 59 mg C m−2 h −1 were found in the coarser, more stable sediment of the inner bay. Low production in the vicinity of the mouth of a flood control channel is thought to be caused by heavy metal inhibition in conjuction with sediment instability, a shl/allow photic zone and heavy grazing pressure. Seasonal production peaks in spring and falll were found to be closely correlated with the concentration of nitrate and silicate but not with phosphate. This study shows that even though Bolsa Bay has been cut off from the sea, drained and subjected to fill, it is as productive as other coastal wetlands throughout the world.
PHENOTYPIC PLASTICITY IN DRAPARNALDIA (CHLOROPHYTA: CHAETOPHORACEAE). I. EFFECTS OF THE CHEMICAL ENVIRONMENT1
Authors: Jojmstone Iam M. 
Published: April 2006

ABSTRACTEight axenic isolates of Draparnaldia spp. were in defined media under controlled condidom of day length, light intensity and temperature to study effects of the nutrientions on genera; pheuotype and development of main text cells. Phosphate (0–6,8 mg/l P), magnesium (0‐9.6 mg/l Mg), sulfate (1.2 –14.0 mg/l S) and chloride (0.2‐48.2mg/l Cl) had no effect. Small, but significant, concentration‐independent, isolate‐specific differences due to sodium and patassium (as the phosphate salt) occured in main axis cell length. The presence of calcium (>1.7 mg/l) was required by all isolates for main axis differentiation. In the absence of calcium, only zoospores and stunted Stigeoclonium‐ like plants were produced. Nitrate (>5 mg/l N) depressed main axis cell size;at higher levels (> 15 mg/l N) hair prooduction was depressed and several isolates developed a very typical Cloniophora appearance, Several of the isolates did not produce typical Draparnaldia‐ like phenotypes under any of the chemical formulations tried; therefore, it is suggested that chemical factors alone do not account for either the phemotypec plasticity of Draparnaldia in the field or the failure of others to grow typical plants in culture.
OLSTHODISCUS LUTEUS (CHRYSOPHYCEAE) II. FORMATION AND SURVIVAL OF A BENTHIC STAGE1
Authors: Tomas Carmelo R. 
Published: April 2006

ABSTRACTMotile unicells of Olisthodiscus lutheus Carter aggregated to form encapsulated masses of nonmotile cells in a benthic stage throughout a temerature range of 15–30°C at salinities o f 10–50%. Motile cells were released from beneathic masses at 10–30°C but at 5°C, cells were not motile and at 0°C cells lysed. Exposure of benthic masses of I day to 8 wk to temperatures of 0–30C in lighted growth chambers resulted in mortality to cells kept below 10°C and normal growth at higher temperatures. Benthic stage cells kept tn darkness at the same temperatures exhibited mortality in all but those at 5 and 10°C. Cells at these thmoeratures remained viable 15 wk in continual darkness. Comparison of cell morphology of matile and benthic stage O. luteus to other Olisthodiscus species and the ecological implications o fthe benthic stage are discussed.
AMMONIUN AND NITRATE UPTAKE BY THE MARINE MACROPHYTES HYPNEA MUSVUFORMIS (RHODOPHYTA) AND MACROCYSTIS PYRIFERA (PHAEOPHYTA)1, 2
Authors: Haines Kenneth C. , Wheeler Patricia A. 
Published: April 2006

ABSTRACTNH4+ and NO3− uptake were measured by continuous sampling with an autoanalyzer. For Hypnea musciformis (Wulfen) Lamouroux, NO3−up take followed saturable kinetics (K2=4.9 μg‐at N t−1, Vmax= 2.85 μg‐ at N, g(wet)−1. h−1. The ammonium uptake data fit a trucatd hyperbola, i.e., saturation was not reach at the concentrations used. NO3− uptake was reduced one‐half in the presence of NH4+, but presence of NO3− had no effect on NH4+ uptake. Darkness reduced both NO3− and NH4+ uptake by one‐third to one‐half. For Macrocystis pyrufera (L) C. Agardh, NO3− uptake followed saturable kinetices: K2=13.1 μg‐at N. l−1. Vmax=3.05 μg‐at N. g(wet)−1. h−1.NH4+ uptake showed saturable kinetics at concentration below 22 μg‐at N l ‐1 (K2=5.3 μg‐at N.1–1, Vmax= 2.38 μg‐at N G (wet)−1.h−1: at higher concentration uptake increased lincarly with concentrations. NO3−and NH4+ were taken up simulataneously: presence of one form did not affect uptake of the other.
PHOTOINHIBITION OF PHOTOSYNTHESIS IN ASTERIONELLA FORMOSA (BACILLARIOPHYCEAE)1, 2
Authors: Belay Amha , Fogg G. E. 
Published: April 2006

ABSTRACTA laboratory study was made of the inhibition of photosynthesis, as measured by the radiocarbon method, of Asterionella Formosa Hass. by light from tungsten halogen lamps of irradiances up to that of full sunlight. The observed inhibitions were of total fixation of carbon and were not due to greatly increased release of extracellular products of photosynthesis. Inhibition increased width irradiance and with time of exposure. It was greater at high temperature, at high oxygen concentrations and when the cells were nutrient deficient. Recovery from exposure to high irradiances took place both in the dark and at low irradiances. The inhibition, which is similar to that observed under natural conditions, has the characteristics of photooxidative damage to both photochemical and dark reaction mechanisms.
MOLECULAR, ENZYMATIC AND ULRASTRUCURE CHARACTERIZATION OF THE PYRENOID OF THE SCALY GREEN MONAD MICROMONAS SQUAMATA1,2
Authors: Salisbury Jeffrey L. , Floyd Gary L. 
Published: April 2006

ABSTRACTPyrenoid material of micromonas squamata Manton & Parke was obtained free of cell and subcellular particle conamination by differential centrifugation of brei from osmoically lysed cells. The isolated pyrenoid particles were characterized by transmission and scanning electron microscopy. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of pyrenoid extracts revealed a compled polypeptide composition with major components of 12, 54 and 66 kilodalton mol wt. Whole pyrenoids possessed the enzymatic properties of ribulose diphosphate carboxylase and fixed carbon dioxide with specific activity 10 times greaer than that of a pyrenoid‐free high speed supenaant fracion of cell brei. Energy dispersive X‐ray microanalysis revealed he presence of copper in masses of cryo‐impacted pyrenoid material. Ultrastrucural cytochemistry was employed o determine he chemical nature of the reserve carbohydrate shell. Also, the pyrenoid of the intact cell was characterized by transmission electron microscopy.
SCANNING ELECTRON MICROSCOPE OBSERVATINS ON ZOOSPORANGIAL ABSCISSION IN PHYCOPELTIS EPIPHYTON (CHLOROPHYA)1
Authors: Good Barry H. , Chapman Russell L. 
Published: April 2006

ABSTRACTZoosporangial abscissin in asexually reproductive Phycopeltis epiphyon, Millardet, epiphytic on leaces of Osmanhus fragrans Loureiro and Sabal minor (Jacquin) Person, examined with scanning electron micrsscopy is described and compared with the process in related Cephaleuros virescens Kunze. The laeral wall of he zoosporangium‐pedicel septum begins to rupure early in he abscission process and is followed by continued learing of the lateral wall and partial spliing of the septum. The zoosporangium remains attached in a hinge‐like fashion to the pedicel by a portion of the lateral wall and septum. A centrally located protuberance emerges from wihin the septa of both the zoosporangium and pedicel, and together with a slight bulging of the septa, is involved in the final separation of the zoosporangium. Although there are differences in surface morphlogy of identical in P. the zoosporangia and the location of the exit pores, the process of abscission is identical in P. epiphyton and C. virescens.
COMPARATIVE STUDY OF LUMINESCENT AND NONLUMINESCENT STRAINS OFGONYAULAX EXCAVATA(PYRRHOPHYTA)1,2
Authors: Schmidt Robert J. , Gooch Van D. , Loeblich Alfred R. , Hastings J. Woodland 
Published: April 2006

ABSTRACTThree of ten cultures ofGonyaulax excavata(Braarud) Balech isolated from the 1972 New England red tide are nonluminescent, Biochemical components of dinoflagellate bioluminescence were not detected in the extracts from these three isolates. Cells of the nonluminescent cultures were identical to those of luminescent cultures as compared by light microscopy, major body plate tabulation, cell size and growth. Both luminescent and nonluminescent cells were toxic as determined by using the mouse bioassay for paralytic shellfish poisoning. All the 122 clones made from one of the luminescent isolates were luminescent suggesting this feature is a stable trait. We conclude that these isolates represent luminescent and luminescent strains ofG. excavata.This is the first intraspecific investigation of in vitro bioluminescent components between nonluminescent and luminescent strains of a dinoflagellate.
FIELD AND CULTURE STUDIES ON GROWTH AND REPRODUCTION OF CALLITHAMNION BYSSOIDES (RHODOPHYTA, CERAMIALES) IN NORTH CAROLINA1,2
Authors: Kapraun Donald F. 
Published: April 2006

ABSTRACTThe life history of Callithamnion byssoides Arnott ex Harv. in Hook. from North Carolina is shown to be of the Polysiphonia‐type. Cross‐gradient light‐temperature culture in 8:16 and 14:10 LD cycles was utilized to investigate the effects of light intensity, temperature and day‐length on growth and reproduction. Carposporophyte and tetrasporangium development were controlled by total light energy rather than photoperiod. Results of these studies explain the observed seasonal periodicity of growth and reproduction on the North Carolina coast. Variations between these results and previously published data for this species in Texas are explained in terms of ecotypic differentiation.
ENHANCED TRANSPORT OF INORGANIC CARBON INTO ALGAL CELLS AND ITS IMPLICATIONS FOR THE BIOLOGICAL FIXATION OF CARBON1,2
Authors: Lehman John T. 
Published: April 2006

ABSTRACTKinetics of uptake of inorganic carbon by the freshwater green algaChlamydomonas reinhardtiiDang. suggest that rates of fixation may be enhanced at low tensions of CO2by transport of bicarbonate from the cell surface to the chloroplast. Results are evaluated in the context of models that treat diffusion and reaction of dissolved inorganic carbon across a 3 dimensional finite boundary layer, and they are consistent with the claim that CO2alone is the substrate used during carbon fixation. An alternative hypothesis, which presumes that both CO2and bicarbonate are used as substrates, yields predictions which are inconsistent with the data. Instead, bicarbonate seems to act only as a vehicle for the transport of inorganic carbon into the cell, thereby adding its flux to that of CO2, and enhancing rates of synthesis that would otherwise be restricted by uptake of CO2alone.
ASSOCIATION OF PLEUROCAPSA AND CALOTHRIX (CYANOPHYTA) IN A THERMAL STREAM1,2
Authors: Wickstrom Conrad E. , Castenholz Richard W. 
Published: April 2006

ABSTRACTA crustose, nodular mat, primarily composed of Calothrix sp. and Pleurocapsa sp., occurs in some alkaline hot springs of the western United States. Together, these species constituted ca. 71% of the mat biomass; the remainder was partitioned between other cyanophytes and bacteria. Their temperature growth ranges in culture were 24–50 C (Calothrix) and 30–55 C (Pleurocapsa). Both clonal cultures had maximal growth rates at 45 C (Pleurocapsa, 1.28 doublings/24 h; Calothrix 2.30). Calothrix grew at approximately twice the rate of Pleurocapsa throughout their coincidental temperature range. The relative proportions of Calothrix (42%) and Pleurocapsa (27%) were constant in a thick mat (ca. 1 mm) regardless of season; however, a thin mat (ca. 0.5 mm) contained significantly more Pleurocapsa (71%) and less Calothrix (5%). Analysis of 10 μm thick microtome sections showed that Pleurocapsa dominated the innermost region (substrate side) of the nodule mat while Calothrix abundance increased from ca. 3% in this region to 80–96% at the surface of thick mat samples (ca. 0.8–2.3 mm). Our proposed that the grazing pressure exerted by an ostracod population accounts for the continued coexistence of and the observed spatial relationships between these species appears most consistent with the observations.
DIFFERENTIATION OF LAMBDA CARRAGEENANS FROM RHODOPHYTA WITH IMMUNOLOGICAL AND SPECTROSCOPIC TECHNIQUES1
Authors: J. Evelegh M. , Vollmer C. M. , McCandless E. L. 
Published: April 2006

ABSTRACTKCl soluble carrageenans from sporophytes of twoGigartinaspecies were differentiated from those ofChondrus crispusStackhouse,Iridaea cordata(Turner) Bory,Rhodoglossum californicum(J. Ag.) Abbott, and twoPetrocelisspecies by their failure to precipitate on immunodiffusion against either of two absorbed anti‐λ–carrageenan antisera. The carrageenans have been analyzed by infrared spectroscopy, and on this basis it is postulated that the antibody preparations recognize sulphate on C‐6 of the carrageenans. TheGigartinacarrageenans appear to lack sulfate at this position.
STUDIES ON GRACILARIA (GIGARTINALES, RHODOPHYTA): REPRODUCTIVE STRUCTURES1,2,3
Authors: Edelstein T. , Chen L. C. ‐M. , McLachlan J. 
Published: April 2006

ABSTRACTThe reproductive structures of Gracilaria foliifera (Forsk.) Børg. from England and an unnamed species of Gracilaria from Nova Scotia were studied by light microscopy. These two entities are distinguishable on the basis of the type of gonimoblast tissue in their mature cystocarps. This, together with other evidence, suggests that these are separate taxa.