bluuebunny/crossref_metadata_2025 huggingface dataset:
EXISTENCE OF ADERBESIAPHASE IN THE LIFE HISTORY OFHALICYSTIS OSTERHOUTIIBLINKS AND BLINKS1,2,3
Authors: Page Joanna Ziegler
Published: April 2006

Halicystis osterhoutiiis shown to be the gametophytic generation of aDerbesiaspecies; problems involved in the identification and nomenclature of this species are discussed.
SURVIVING PROTOPLASTS IN VITRO AND THEIR DEVELOPMENT IN BRYOPSIS1
Authors: Tatewaki Masakazu , Nagata Kôichi
Published: April 2006

In the coenocytic marine alga Bryopsis plumosa, extracellular protoplasts synthesize new cell walls in vitro and can develop into normal pinnate plants in the same way of the zygote of this species.
PROLONGED VIABILITY OF OEDOCLADIUM AKINETES1
Authors: Davis Joseph S.
Published: April 2006

Dry 3.5‐yr‐old akinetes of Oedocladium packed with carotenoid pigments, fat and starch, became green and reproduced like ordinary vegetative cells when they were placed in a defined mineral medium.
THE DISCOVERY OFHALICYSTIS OVALIS(LYNGBYE ARESCHOUG IN NEW ENGLAND1,2
Authors: Mathieson Arthur C. , Burns Richard L.
Published: April 2006

Halicystis ovalisis recorded for the first time on the northeast coast of North America, from 12–24 m on the exposed open coast of New Hampshire.
NITROGEN UPTAKE BY FUCUS SPIRALIS (PHAEOPHYCEAE)1,2
Authors: Topinka Bigelow Jerry A.
Published: April 2006

Ammoniun, nitrate and nitrite update by Fucus spiralis L. from the Massachusetts coast was examined. Uptake of all appeared to follow saturation type nutrient uptake kinetics, with uptake often restricted at ambient nutrient concentrations. Although only relatively large difference in K8 values could be easily distinguished, K8 values for NO3− and NH4+ were generally similar and low compared with NO2−. There was also some suggestion that K8 was reduced at lower temperatures. At 15 C. Vmax for light and dark uptake for both NH4+ and NO3−, and light uptake of N02− were similar, suggesting comparable potential use at higher concentrations. Ammonium and NO3−uptake decreased at lower temperatures giving Qro values of 1.8 and 1.6, respectively, between 5 and 15°C. Nitrate and NH4+ were taken up together and high levels of NH4+ did not inhibit NO3− uptake. Light did not affect uptake of either but did stimulate NO2− uptake. Ammonium and NO3− uptake were highest in apical frond and whole young plants, and lowest in slower growing, older frond and stipe. On a relative basis. NO3−, NH4+ and NO2− were estimated to have contributed ca. 59, 39 and 2% respectively, to the yearly N uptake by apical frond. During winter, NO3− would provide ca. twice the N to F. spiralis as would, NH4+. From summer to early fall, when NO3− levels are lower, NO3− and NH4+ would be used in comparable amounts.
DIATOM PRODUCTIVITY COMPARED TO OTHER ALGAE IN NATURAL MARINE PHYTOPLANKTON ASSEMBLAGES1,2
Authors: Thomas William H. , Dodson Anne N. , Reid Freda M. H.
Published: April 2006

Total productivity rates and the component attributed to the diatom proportion in the crop were measured in natural water samples taken from the Scripts Pier (La Jolla, California) at ca, monthly intervals in 1975–76. Two other measurements were done in water samples taken from Saanich Intel, Vancouver Islands, British Columbia (Canada). The percent of photosynthesis by diatoms was compared with the proportion of diatom carbon in the crop. In all instances, percent diatom photosynthesis was higher than percent diatom carbon for dialoms were higher than those of other algae. It is hypothesized that, in the sea, diatoms can outcompete other algae. However, the assemblages consist of some tens of species coexisting, and no portion of the crop out competes the others to exclusion.
NUTRITIONAL STUDIES OF TWO RED ALGAE. II. KINETICS OF AMMONIUM AND NITRATE UPTAKE1,2
Authors: D'Elia Christopher F. , DeBoer James A.
Published: April 2006

Similar NH4+and NO3−.uptake kinetic patterns were observed inNeoagardhiella baileyi(Harvey ex Kiitzing) Wyinne & Taylor and Gracilaria foliifera (Forssk?l) Borgesen. NO3−was taken up in a rate‐sturating fashion described by the Michaelis‐Menten equation. NH4+uptake was multicomponent: a saturable component was accompanied by a diffusive or a high K component showing no evidence of saturation (at ≤50 μM [NH4+]). Nitrogen starved plantsi(C/N atom ratios > ca. 10) showed higher transient rates of NH4+uptake at a given concentration than plants not N‐Iimited. Only plants with highNcontent exhibited diel changes inNH4+uptake rates, and showed transient rates of NH4+accumulation which did not greatly exceed the capacity to incorporate N in steady‐state growth. NH4+was preferred over NO3−even in plants preconditioned on NO3−as the sole N. source, NO3−uptake was suppressed at 5μM [NH4+], but simultaneous uptake occurred at unsurpressed rates at lower concentrations. Potential for N accumulation was greater via NH4+uptake than via NO3−uptake. Changing capacity for NH4+uptake with N content appears to be a mechanism whereby excessive accumulation of N was avoided by N‐.satiated plants but a large accumulation was possible for N‐depleted plants.
TOXICITY OF BISULFITE TO PHOTOSYNTHESIS AND RESPIRATION1
Authors: Sheridan Richard p.
Published: April 2006

Inhabition of photosynthesis in Chloroccoum sp by bisulfileion was the reciprocal of the light intensity curve. Respiration was least affected of the bisulfite after endogenous substrate was reduced by incubation in darkness. Maximum areduction in growth occurred with bisulfile treatment at or above optimal growth temperatures. Maximum phytotoxicity correlated with conditions resulting in maximum metabolic activity. The order of toxicity was –H2SO3HSO3−SO3.
LIFE HISTORY OF BONNEMAISONIA CENICULATA (RHODOPHYTA): A LABORATORY AND FLELD STUDY1, 2
Authors: Shevlin Dennis E. , Polanshek Alan R.
Published: April 2006

Cystocarpic and spermatangial plants of rarely reported red alga Bonnemaisonia geniculata Gardner, epiphytic on Odonthalia Aoccosa (Esp.) Falk, were collected from june to September 1975 at shell Beach, california. Carpospores inoculated into unialgal culture divided, upon germination, in to two daughter cells, both of which formed erect and rhizoidal axes, Erect axes were uniseriale and alternately branched with a distictive zigzag pattern of axial cells. No tetrasporangia developed in culture. The presumptive tetrasporangia developed in culture to a described genus. Plants morphologically similar to those cultured from carpospores were found at the collection site; they bore tetrasporangia from February to june. Cullured letrasporews gave rise to male and female plants similar to those of field‐collected B. geniculate in ca. a I:I ratio. Fertile female plants in the presence of male plants formed cystocarps. Carpospores gave rise to the alternately branched tetrasporophyte phase. Bonnemaisonia geniculate has a heteromorphic life history involving a previously undescribed tetrasporophyte.
FINE STRUCTURE OF THE ZOOSPORE OF OEDOCLADIUM CAROLINIANUM (CHLOROPHYTA) WITH SPECIAL REFERENCE TO THE FLAGELLAR APPARATUS1, 2
Authors: Marhowitz Melvin M.
Published: April 2006

Ultrastructure of the motile zoospore has been investigated in Oedocladium catolinianum & Hoffman. An unwalled zoospore is usually produced from the contents of a terminal vegetative cell and consists of two principal regions: a small anterior dome and a larger body region; a ring of flagella marks the juncture of these two areas. Chloroplast inclusions consist of thylakoids, mature and incipient pyrenoids, starch and striated microtubules; no eyespot has been observed. Zoospores appear to possess permanent contractile vacuoles with numerous accessory vacuoles, coated vesicles and occasionally coated tubules. The cytoplasm of the dome contains numerous mitochondria

ER and golgi bodies, as well as two distinct types of vesicles. The first contains an electron‐dense; granular core and is surrounded by a loose, sinuate membrane. The second vesicle is electron‐opaque and is found at the apex of the dome: it contains mucopolysaccharides employed during zoospore adhesion. A complex flagellar apparatus encircles the lower region of the dome. It consists of ca. 30–65 flagella, a ring‐shaped fibrous band, flagella roots and additional supporting material. The flagella and roots alternate with one another beneath the fibrous band. The compound flagellar roots consist of two superimposed components: an outer ribbon‐like unit composed of three microtubular elements and a single striated inner component. A band of support material lies beneath the proximal end of the basal bodies. It is a continuous fibrous band, although it often appears as three distinct, repetitive units.
CALCIFICATION AND CATION SORPTION OF CLADOPHOHA GLOMERATA (CHLOROPHYTA)1, 2
Authors: Sikes C. Steven
Published: April 2006

Clacium sorption by Cladophora glomerata (L.) Kutz grown in continuous‐flow culture increased substantially as the alga aged (12.3–160 mg Calg dry wt). This reflected increased pectin layered in thickening cell walls followed by deposition of CaCO3 around cells. The high levels of pectin (up to 23% of dry wt) may account for the plant's reported high affinity for cations. The onset of carbonate deposition coincided with the appearance of carbonabic anhydrase activity in cells. This suggests that carbonate deposition mey be a funtion of bicarbonate use as a source of CO2 for photosynthesis. Calcium uptake appears to occur by active transport in that it exhibited saturation kinetics, occurred against a concentration gradient, depended on light, and was nearly abolished by treatments that allow diffusion. Although strontium competed for Ca for binding sites of pectin, it did not inhibit intermal transport of Ca. Consequently, the proposed carrier may be specific for Ca.
COEXLSTENCE OF TOXIC AND NONTOXIC DINOKLAGELLAIES RESEMBLING GQNYAULAX TAMARENSIS IN NEW ENCILAND COASTAL WATERS (NW ATLANTIC)1
Authors: Yentsch Clarice M. , Dale Barrie , Hurst John W.
Published: April 2006

Two forms resembling Gonyaulax tamarrensis Lebour coexist in Maine cosat plankton; one is toxic, the other is nontoxic. At times, red patches of dinoflagellates were identified as G. tamarensis, yet only presumed to he toxic. Toxic froms were found in June, July 1975 and 1976. The nontoxic form was found in a more esraurine area, e.g., mid‐July 1975, early July 1976. These two forms are not easily distinguished by conventional microncopic ohservation, nor by pigment analysis. Preliminary observations suggest that the nontoxic form is smaller than G. excavata (Braarud) Balech and tacks the “excavated” ventrat region. Characteristic G. excavata resting cysts were found in sediment from the shellfish toxic area off Newagen and Monhegan (Maine) and were not found in sediments from areas where the nontoxic form bloomed. There appear to be a minimum of two G. tamarensis‐like organisms. Full systematic treatment of these must await further information.
EFFECTS OF ARSENATE ON GROWTH AND PHOSPHORUS METABOLISM OF PHYTOPLANKTON1,2
Authors: Planas Dolores , Healey F. Patrick
Published: April 2006

The response to arsenate in growth and phosphate uptake by five algae in culture varied considerably. The growth rates of Melosira granulata var. angustissima O. Müll, and Ochromonas vallesiaca Chodat were depressed by 1 μM arsenale. Chlamydomonas reinhardtii Dang. required 10 μM for the same degree of depression, while the growth rules of Cryptomonas eroasa Ehr. and Anabaena variabilis Kütz. were unaffeted up to 100 μM. However, following depletion of phosphate, cultures of the later two algae began to die at the higher concentrations of arsenale tested. Growth of C. reinhardtii in the presence of 35 μM arsenate resulted in characteristics of P deficiency. Comparison of rates of photosynthesis, respiration, and phosphate uptake between cultures of C. reinhardtii which had grown in the presence and absence of arsenate showed little evidence after 16 doublings that it had adapted to arsenale.
GROWTH‐INFLUENCING SUBSTANCES IN SEDIMENT EXTRACTS FROM A SUBTROPICAL WETLAND: INVESTIGATION USING A DIATOM BIOASSAY1
Authors: Cooksey Keith E. , Cooksry Barbara
Published: April 2006

A Biological assay using Amphora coffeaeformis var. perpusilla (Grunow) Cleve and A. coffeaeformis (Agardh) Kützing was used to investigate the changes in the properties of soluble organic carbon in sediments taken from a coastal wetland. During January to May, sediment extracts became increasingly inhibitory to diatom growth After the onset of the spring rains, the inhibitory properties of the extracts disappeared. Substances capable of promoting mixotrophic growth and heterotrophic growth were found in extracts taken in July to December. These positive responses took place at the time of mangrove (Rhizophora mangle L.)leaf‐fall.
SEAWEED ANATOMY AND PHOTOSYNTHETIC PERFORMANCE: THE ECOLOGICAL SIGNIFICANCE OF LIGHT GUIGES, HETEROGENEOUS ABSORPTION AND MULTIPLE SCATTER12
Authors: Ramus J.
Published: April 2006

Light absorption by two green seaweeds with similar photophysiology but different anatomies are compared: i) Ulva lactuca var. rigida (C. Ag.) Le Jolis, an optically translucent species of two cell layers both bearing chloroplasts; and, ii) Codium fragile subsp. tomentosoides (van Goor) Silva, an optically opaque species with a colorlelss medulla surrounded by a cortex of choloroplast‐bearing utriclels. Thallus absorptance (fraction of incident light absorbed) was measured for various pigment contents. Absorptance by U. lactuca was dependent on pigment concentration in an exponential manner and never exceeded 0.6, whereas absorptance by C. fragile was independent of pigment concentration and always approached a balue of 1.0. Water in the medullary tissue of C. fragile is often of the utricles. The utricles appear to be “integrating spheres” enhancing the capture of incident light, aided by the wave‐guide function of the thin peripheral layer of cytoplasm and a reflector function at their base. Photosynthitic performance for U. lactuca saturates at high light intensities and attenuates rapidly with decreasing intensities. In contrast, photosynthetic performance for C. fragile saturates at low light intensities and attenuates slowly with diminishing radiation. Extrapolated diel variation in photosynthesis shows that U. lactuca's anatomy is adaptive for high light intensity environments, whereas C. fragile's anatomy is adaptive for low light intensity environments. Both seaweeds fit into the ecological category of “fugitive” species, and compete in the Long Island Sound (Atlantic Ocean) rocky intertidal for free‐space. Predictions are presented for relative species abundances along a monotonic gradient of light intensity.
PSEUDOHIMANTIDIUM PACIFICUM, AN EPIZOIC DIATOM NEW TO HE FLORIDA CURRENT (WESTERN NORTH ATLANTIC OCEAN)1, 2
Authors: Gibson Robert A.
Published: April 2006

The marine epizoie diatom, Pseudohimantidium pacificum Hustedt & Krasske, is reported for the first time in Florida Current waters of the Western North Atlantic Ocean off the east coast of Florida. The diaom was fround attached to indivieuals of copepod species in the orders Harpacicoida and Cyclopida.
THE POLYMORPHIC DIATOM PHAEODACTYLUM TRICORNUTUM: ULTRASTRUCTURE OF ITS MORPHOTYPES1,2
Authors: Borowitzka Michael A. , Volcani Benjamin E.
Published: April 2006

The ultrastructure of the oval, fusiform and triradiate morphotypes of Phaeodactylum tricornutum Bohlin is described. The organization and structure of the cytoplasmic organelles is similar in all three morphotypes, except that the vacuoles occupy the extra volume created by the arms of the fusiform and triradiate cells. The frustule in fusiform and triradiate cells is organic; in the oval type it may be organic or one of the valves may have a silica frustule surrounded by an organic wall. In all cells, the organic cell wall has up to 10 silica bands (13 nm wide) embedded in its surface in the girdle region, lacks girdle bands, and has an outer corrugated cell wall layer, except in the girdle region. Cell division, organic wall formation and silica deposition are described in detail. Four types of oval cells are also described. The relation to other diatoms is discussed.
MORPHOLOGIC AND TAXONOMIC OBSERVATIONS ONNEOAGARDHIELLA(GIGARTINALES, RHODOPHYTA), WITH EMPHASIS ON PACIFIC POPULATIONS1,2
Authors: Abbott Isabella A.
Published: April 2006

Agardhiella coulteri(Harvey) Setchell (Solieriaceae) from the Pacific coast of North America is presently included in the circumscription ofNeoagardhiella baileyi(Kützing) Wynne & Taylor from the Atlantic and the Gulf of Mexico. Examination of fresh, liquid‐preserved and dried Pacific material has shown a different medullary and cystocarpic structure from specimens in eastern North America. The Pacific specimens are being removed fromN. baileyitoN. gaudichaudiicomb. nov., based onGigartina gaudichaudiiMontagne, the oldest available name for the Pacific material. Included inN. gaudichaudiiisAgardhiella mexicanaDawson from the Gulf of California (Mexico), and South American specimens formerly included in A.tenera(J. Agardh) Schmitz.
ULTRASTRUCTURE OF THE FRUSTULE OF TRICERATIUM FAVUS (BACILLARIOPHYCEAE)1,2
Authors: Miller William I. , Collier Albert
Published: April 2006

New structural details of the frustules of the diatom Triceratium favus Ehrenberg seen in the scanning electron microscope are reported. Significant new observations concern the pores of the hexagonal chambers, accessory structures (spines, dendritic processes) on the outer surfaces of the hexagonal chambers, the value margins and girdle structure.
CHAIN‐FORMING DIATOMS: THREE SPECIES OF CHAETOCERACEAE1,2
Authors: Fryxell Greta A.
Published: April 2006

Bacteriastrum furcatum Shadbolt, Chaetoceros bacteriastroides Karsten and C. pseudocurvisetum Mangin are each connected in chains by fusion of silica between setae. The first two have specialized heterovalvate end cells indicating physiological control of the length of chains, but chains of C. pseudocurvisetum have usually been seen broken. There are specialized deeply lobed connecting bands in B. furcatum and C. pseudocurvisetum, allowing the setae of sibling valves to protrude outside the diameter of the chain during their formation. C. bacteriastroides and C. pseudocurvisetum are not identical; differences include presence of small setae, fusion of large setae some distance from the valves, symmetry of apertures between cells, and straight chains of C. bacteriastroides, compared with valve mantle connections with no small setae, large setae joined by crossing over, asymmetry of windows between cells, and curved chains of C. pseudocurvisetum. The evolutionary direction is hypothesized to be from Bacteriastrum to Chaetoceros through C. bacteriastroides.
ULTRASTRUCTURE OF THE RED TIDE DINOFLAGELLATE GYMNODINIUM BREVE. I. GENERAL DESCRIPTION1,2,3
Authors: Steidinger Karen A. , Truby Earnest W. , Dawes Clinton J.
Published: April 2006

Gymnodimium breve Davis, an unarmored marine dinoflagellate has a cell covering (theca) composed of four membranes. The inner two membranes represent a vesicular layer and in tangential section, the theca appears composed of polygonal areas. Unusual threat ridges are located in the cingular region between the epi‐ and hypocone. This osmotically sensitive species is extremely vesiculate with dispersed areas of cytoplasm containing typical eukaryotic organelles as well as other organelles found only in dinoflagellates. The non‐vesiculated cytoplasm is continuous in serial sections. The chloroplasts can contain either quasi‐radial or parallel lamellae typically consisting of three thylakoids each. The pyrenoid is multiple‐stalked and lacks a starch cap. The dinophycean pusule is simple and similar to those found in several unarmored marine species. The nucleus is typically dinophycean but the chromosomes appear to lack nonfibrillar material.
UPTAKE OF ORGANIC SUBSTRATES BY CYCLOTELLA CRYPTICA (BACILLARIOPHYCEAE): EFFECTS OF IONS, IONOPHORES AND METABOLIC AND TRANSPORT INHIBITORS1,2
Authors: Hellebust Johan A.
Published: April 2006

The uptake of glucose and amino acids by the euryhaline diatom Cyclotella cryptica Reimann, Lewin & Guillard does not appear to be related to proton gradients. Instead, the transport systems for these organic solutes show a strong requirement for the presence of NaCl. The relationship between uptake and NaCl concentration is hyperbolic, with optimal uptake rates being approached at 100 mM NaCl. High concentrations of KCl cause strong reductions in uptake rates. The (Na+, K+)‐stimulated ATPase inhibitor ouabain has no effect on glucose uptake, whereas the diphenolic glucoside phlorizin and its aglucone phloretin are strongly inhibitory. The proton translocating uncoupler CCCP (carbonylcyanide m‐chlorophenyl hydrazone) and the ATPase inhibitor DCCD (dicyclohexylcarbodiimide) both almost completely abolish glucose transport, and low concentrations of the ionophares monensin and valenomycin strongly inhibit glucose uptake by the diatom. The requirement of high external NaCl concentrations for glucose transport, and the inhibitory effect an transport of the Na+‐specific ionophore monensin are consistent with a coupling of Na+ and organic substrate transport, but could also be explained by a Na+ requirement for glucose binding to a transport carrier, and/or a possible interference with energy producing reactions associated with a monensin‐induced collapse of the normal Na+ gradient.
GROWTH OFULVA FENESTRATA(CHLOROPHYTA) IN MICROCOSMS RICH INZOSTERA MARINA(ANTHOPHYTA) DETRITUS1,2
Authors: Harrison Paul Garth
Published: April 2006

In laboratory experiments discs cut from thalli ofUlva fenestrataPostels & Ruprecht grew in diameter and biomass (dry weight and ash‐free dry weight) more when dead leaves ofZostera marina L.were present than when absent. A maximum increase in dry weight of 500% in 14 days occurred withZosterapresent compared with only a 200% increase with no detritus. When NO−3and PO3‐4were added the weight of anUlvadisc increased by over 800% whenZosterawas present but by only 400% in controls. In general penicillin G (475 units/ml) caused a reduction in algal growth in cultures containing detritus. It is concluded that bacteria on the detritus may compete with algae for nutrients but by releasing unknown substances the bacteria promote the growth ofUlva.
ULTRASTRUCTURE OF NOCTILUCA MILIARIS (PYRROPHYTA) WITH GREEN FLAGELLATE SYMBIONTS1,2
Authors: Sweeney Beatrice M.
Published: April 2006

The ultrastructure of the Noctiluca miliaris Suriray from Southest Asian waters which contains the green flagellate, Pedinomonas noctilucae (Subrahmanyan) Sweeney, is in all major respects similar to that of the European strain. New details of the thecal vesicles, pellicle and underlying microtubules are presented. The possibility that the lipid vesicles are identical with the strongly phase‐retarding bodies in the surface cytoplasm, some of which are “microsources” of bioluminescence, is suggested.
MITOSIS AND CYTOKINESIS IN SESSILE SPORANGIUM OFTRENTEPOHLIA AUREA(CHLOROPHYCEAE)1
Authors: Graham Linda E. , McBride Gordon E.
Published: April 2006

An ultrastructure study of mitosis and cytokinesis in the sessile sporangium ofTrentepohlia aurea(L.) Mart, was made to clarify the phylogenetic position of the alga. Mitosis was closed and centric at late anphase with cytokinesis involving the production of cleavage membranes by dictyasames between the numerous, well‐separated daughter nuclei. Neither phycoplast nor phragmoplast microtubules were observed during cytokinesis. The lack of phycoplast microtubules and the presence of multilayered structures in flagellated cells suggestTrentepohliais phylogenetically related to those green algae thought to have given rise to the land plants. The primitive type of mitosis and the lack of microbodies suggest that the ancestors ofTrentepohliamay have branched off from this line relatively early.
DIVERSITY IN THE MECHANISM OF CARBON DIOXIDE FIXATION INDUNALIELLA TERTIOLECTA(CHLOROPHYCEAE)1
Authors: Mukerji D. , Glover H. E. , Morris I.
Published: April 2006

The mechanism of photosynthetic carbon dioxide fixation in the green flagellateDunaliella tertiolectaButcher varies during growth in batch culture. Evidence for this change comes from three sources: i) algae from the stationary phase incorporated a greater proportion of the fixed carbon into amino arids and protein than did cells from the mid‐exponential phase; ii) the activity of phosphoenolpyruvate carboxylase relative to that of ribulose‐1, 5‐di‐phosphate carboxylase increased with age in batch culture; and, iii) cells from the stationary phase appeared to utilize the bicarbonate ion as the substrate for photosynthesis, whereas those from mid‐exponential phase appeared to utilize fire carbon dioxide. These data suggest that a change of photosynthetic mechanism can occur within a single species of alga, depending on its physiological state.
PHYSIOLOGICAL INVESTIGATIONS ON ALARM ESCULENTA (LAMINARIALES. PHAEOPHYCEAE). IV. INORGANIC AND ORGANIC NITROGEN IN THE BLADE1,2
Authors: Buggeln Richard G.
Published: April 2006

Seasonal variations in nitrate and organic nitrogen content along the wing and midrib of Alaria esculenta (L.) Grev. lamina have been compared with the NO3‐ cycle in the sea and yearly growth pattern of the blade. Throughout the year, organic N is highest in blade meristem, while NO3‐ distribution is less consistent. NO3‐in blades reaches a peak in March (ca. 25–28 μM), whereas maximum relative accumulation, 3,300X ambient seawater level, occurs in October. Content of NO3‐ and organic N in the blade decreases in concert with the decline of seawater NO3‐ in April. The three periods of rapid blade growth are not correlated with a specific organic N content in the blade meristem. Laboratory experiments suggest that low NO3‐ and elevated seawater temperature are not the major factors retarding Alaria blade growth during summer and early fall in nature.
STUDIES OF HAWAIIAN FRESHWATER AND SOIL ALGAE II. ALGAL COLONIZATION AND SUCCESSION ON A DATED VOLCANIC SUBSTRATE1,2
Authors: Carson Johnny L. , Brown R. Malcolm
Published: April 2006

Spatial studies of colonization and succession of soil algae and chemical analyses of the various soils on the cinde cone of Kilauea Iki in Hawaii Volcanoes National Park, Hawaii are outlined. There is a positive correlation between the diversity and quantity of soil algae with nutrient levels and organic matter accumulation in each locale. Three distinct edaphic‐biotic zones existing in this area are differentially revealed by the soil chemical composition, quantity and diversity of soil algae, and as evident variations in higher plant growth and colonization. Varying colonization and successional phases of higher plant growth around standing and fallen tree snags killed by volcanic activity also reflect variations in the soil algal flora. These variations appear largely as a function of differential water interception, absorption, and retention as well as differential accumulation of organic matter, and the initiation of various biogeochemical cycles.
CELL WALL CHEMISTRY AND ULTRASTRUCTURE OF CHLOROCOCCUM OLEOFACIENS (CHLOROPHYCEAE)1,2
Authors: Miller David H.
Published: April 2006

Cell walls of Chlorococcum oleofadens Trainor & Bold were examined ultrastructurally and chemically. The wall of zoospores has a uniform 30 nm width and a regular lamellar pattern. Zoospores and young vegetative cell walk exhibit periodicities, consisting of 20 nm ridges on the outer layer. Vegetative cell walls have a variable thickness of Up to 800 nm and are composed of multiple layers of electron dense material. Further, vegetative walk contain a microfibrillar material composed predominantly of glucose and presumed to be cellulose. Except for this cellulose, vegetative cell wall chemistry is very similar to that of Chlamydomemas being composed of glycoprotein rich in hydroxyproline. The hydroxyproline in Chlorococcum walls is linked glycosidically to a mixture of hetrooligosaccharides composed of arabinose and galactose, and in one instance, an unknown 6‐deoxyhexose. Altogether, the glycoprotein complex accounts for at least 52% of the wall. The amino acid composition of the walls is stikingly similar to those of widely different plant species. Indirect evidence indicates zoospore cell walls are also chemically similar to those of Chlamydomonas, and like them, are cellulose free. Thus a major chemical difference between zoospore and vegetative cell walk of Chlorococcum is the presence of cellulose in the latter. The contribution of this microfibrillar cellulose to the physical properties of the vegetative wall is discussed.
AMINO ACID AND UREA UPTAKE IN TEN SPECIES OF CHLOROPHYTA1
Authors: Kirk David L. , Kirk Marilyn M.
Published: April 2006

The Uptake of radioartively‐labelled mixed amino acids, arginine, lysine, leucine, glutamic acid and urea was examined in six species of Volvocales and four species of Chlarococcales grown in nitrate‐containing medium. Nonradioactive amino acids in excess were used to estimate specificity of amino and carriers in selected cases. All ten species possess salurable (hence, carrier‐mediated) systems for uptake of both arginine and urea. In all Volvacales and one Chlorococcales, the arginine‐speciftc carrier (which also transported lysine with lower efficiency) was the only amino acid carrier detected. Three species of Chlororoccales appear to possess a separate carrier for lysine and two of these appear to possess at least one additional carrier that is involved in uptake of non‐basic amino acids.
ROLE OF INORGANIC IONS IN CONTROLLING SEDIMENTATION RATE OF A MARINE CENTRIC DIATOMDITYLUM BRIGHTWELLI1,2
Authors: Anderson Lars W. J. , Sweeney Beatrice M.
Published: April 2006

The settling rates and intracellular levels of K+, Na+, Cl‐, Mg2+and Ca2+were measured inDitylum bright‐welli(West) Grunow, grown axenically in an enriched seawater medium at 20 C at 4,000 lx on an 8:16 LD schedule. Cells at the end of the dark period have high Na+(118 mM), low K+(64 mM) and low Cl‐(117 mM) relative to levels at the end of the light period when K+(126 mM) and Cl‐(154 mM) are high and Na+(101 mM) is low. There is no significant change in Mg2+(16–18 mM) or Ca2+(3–4 mM) with time. The net result of the ion changes during the light period is to increase cell density by about 3.4 mg ml‐1. This change can account for the increase in settling rate of ca. 0.3 day‐1during the same interval. The density of the cell contents, calculated from observed ion concentrations, is 15–18 mg.ml‐1less than that of the seawater medium. The ion and settling rate changes are light‐dependent and do not persist in the dark or under constant light (ca. 850 lx), but cells do exhibit a free‐running circadian rhythm in cell division under continuous dim illumination. The cell vacuole expands during the light period and contracts during the dark, apparently in response to the net ion fluxes. D. brightwelliappears to regulate its density by active ion selectivity accompanied by trans‐vacuolar water movement.
POTENTIAL IMPORTANCE OF BENTHIC CYSTS OF GONYAULAX TAMARENSIS AND G. EXCAVATA IN INITIATING TOXIC DINOFLAGELLATE BLOOMS1,2,3
Authors: Anderson Donald Mark , Wall David
Published: April 2006

Thick‐walled, nonmotile cysts (termed hypnocysts) of two dinoflagellates were isolated from estuarine sediments in Cape Cod, Massachusetts, and germinated to produce their respective motile, thecate stages. Hypnocysts from Orleans district were identified as Gonyaulax excuvata (Braarud) Balech sensu Loeblich & Loeblich. Visually identical hypnocysts from Falmouth district were provisionally identified as Gonyaulax tamarensis Lebour. Both species were toxic. A geographic survey in September detected hypnocysts in only the sediments of locations where toxic blooms developed the preceding and following Spring. Laboratory incubation (16 C) of hypnocysts from sediment samples stored in the dark (5 C) for 6 mo initiated excystment by the temperature increase, with no appreciable effect from light regime, nutrient, or chelator concentrations. Motility of excysted germlings was optimum in highly chelated medium and in the presence of light. We conclude that hypnocysts of both tasa are important in seeding recurrent annual blooms, synchronizing early bloom development with vernal warning of seawater and increasing the geographic range of the species. We suggest that many red tides in New England and eastern Canadian waters are initiated through the displacement of motile estuarine populations into nearshore area by tidal advection and surface runoff, although the potential existence and importance of offshore cyst reservoirs cannot be discounted. Evidence is presented that hypnocysts are probable sexual zygotes whereas the thin‐walled cysts readily formed in laboratory cultures (pellicle cyst) are asexual. Pellicle cysts are of limited durability, do not overwinter in nature, and therefore do not play a significant role in initiating toxic blooms.
SEXUALITY AND CYST FORMATION IN PACIFIC STRAINS OF THE TOXIC D1NOFLAGELLATEGONYAULAX TAMARENSIS1,2
Authors: Turpin D. H. , Dobell P. E. R. , Taylor F. J. R.
Published: April 2006

Sexuality has been established for a culture ofGonyaulax tarnarensisLebour (strain NEPCC–71). The addition of a thick inoculum to a nitrogen–deprived medium results in the occurrence of anisogamous sexual fusion within the first three days in the new culture. Planozygotes, large “lumpy” cells recognizable by their four flagella, may persist up to 2 wk before forming a smooth–walled, oval hypnozygote. The latter resembles cysts released asexually by ecdysis but has a slightly thicker wall. Viable cysts resembling hypnozygotes (zygotic cysts), but with reduced photosynthetic pigmentation, have been isolated from natural murine sediments in Hidden Basin, British Columbia, and a culture (strain NEPCC–254) was initiated from excysted individuals. Zygotic cysts of NEPCC–71 remained encysted in the light at 17 C for 8 wk before excysting. The presence of a ventral pen with toxicity in the latter strain indicates that the taxonomy ofG. tamarensis‐like organisms is still in a stale of flux and the criteria for recognition ofG. excavata (Braarud) Balech as a separate species are not satisfactory as presently formulated.
COMPARATIVE PHYSIOLOGICAL STUDY OF MARINE DIATOMS AND DINOFLAGELLATES IN RELATION TO IRRADIANCE AND CELL SIZE. I. GROWTH UNDER CONTINUOUS LIGHT1,2
Authors: Chan Augustine T.
Published: April 2006

Cell division rates and chlorophyll a and protein contents for ten diatom and dinoflagellate species were measured. Species were chosen to include a wide range of cell size in terms of both cell volume and cell protein: from 0.004 ng protein/cell for a small Chaetoceros sp. to 2.2 ng protein/cell for Prorocentrum micans Ehrenberg. Experiments were conducted in batch or semi‐continuous cultures at 21 C under continuous illumination from 8–256 μEin .m‐2'.s‐1. Light saturation of cell division occurred at 32–80 μEin m‐1 s‐1 for all species, with no observable difference between the two phylogenetic groups. When the light‐saturated cell division rates were plotted against cell size as protein/cell, the diatoms and dinoflagellates fell on two separate lines with the diatoms having higher rates. Chl a /protein ratios (μg/μg) decreased with increasing irradiance. The diatoms had higher chl a per unit protein. The relationship between cell division rate and the chl a/protein ratio is discussed.
QUALITATIVE ASSAY OF DISSOLVED AMINO ACIDS AND SUGARS EXCRETED BYCHLAMYDOMONAS REINHARDTII(CHLOROPHYCEAE) ANDEUGLENA GRACILIS(EUGLENOPHYCEAE)1
Authors: Vogel Stephanie L. , Frisch Harry L. , Gotham Ivan J.
Published: April 2006

Dissolved amino acids and sugars produced byChlamydomonas reinhardtii Dangeard and Euglena gracilisKlebs were assayed using a combination of radiochromatography and membrane separated spinner flasks. Both species produced similar complements of sugars. The sugars produced In the algae included galactose, glucose, maltose and xylose. The amino acid complements produced Were different for each species. C. reinhardtiiexcreted aspartate, leucine, methionine, phenlyalanine, tyrosine and Valine. E. gracilisexcreted alanine, glutamate, proline and serine. Separation of cells from growth media via membrane filtration produced an overestimate of net amount of dissolved carbon compounds excreted by the cells. However, the radiochromatographic spectra for both filtrates and cell‐free compartments of the diffusion flask experiments were identical. It is hypothesized that the process of filtration max enhance leakage of labeled cellular pools rather than cellular disruption in the species investigated.
FIELD AND CULTURE STUDIES ONGIGARTINA AGARDHII(RHODOPHYTA)1,2
Authors: West John A. , Polanshek Alan R. , Shevlin Dennis E.
Published: April 2006

Cultured carpospores from field‐collected plants ofGigartina agardhiiSelfchell & Gardner gave rise to eitherPetrocelis‐like crustose plants, or basal discs with erectGigartina‐like blades. Made tips excised from field‐collected female plants and cultured in the laboratory also showed two patterns of reproduction: procarpic papillae that only produced cystocarps in the presence of male plants with spermatid, or cystocarpic papillae that formed and released carpospores in the absence of male plants. The first pattern in each case above is evidence for a sexual life history and the second for an apomictic life history similar to that forG. papillata (C. Agardh) J. Agardh. The resorcinol lest for k‐carrageenan was negative forPetrocelis‐like plants and positive for foliose plants providing addition evidence that the former are haploid and the latter diploid as is characteristic for the Gigartinaceae. Crossing experiments between sexual male and female isolates ofG. agardhii fromseveral locations indicated that free interbreeding occurs. All crosses betweenG. agardhiiandGigartina‐phase gametophytes cultured from tetraspores ofPetrocelis middendorffii (Ruprecht) Kjellman were negative demonstrating thatG. agardhiiis reproductively isolated fromG. papillata/P. middendorffiiand represents a distinct species. The tetrasporophytic phase of G. agardhiiin nature is still not known. The significance of reproductive isolation inGigartinasubgenusMastocarpusis discussed. On the bosis of nomenclatural priorityG. agardhiiSetchell & Gardner 1933 is placed in synonymy underG.jardiniiJ.Agardh 1876.
DIFFERENCES IN PHOTOSYNTHESIS‐ASSOCIATED PROPERTIES OF THE BLUEGREEN ALGA SYNECHOCOCCUS CEDRORUM CROWN AT 30 AND 40 C1
Authors: Sherman Louis A.
Published: April 2006

The growth of Synechococcus cedrorum Saug. (UTEX 1191) at 40 C resulted in structural and functional alteratons relative to cells grown at 30 C. Structural variations included cell morphology and the chemical composition of the membrane. Growth at 40 C. produced cells that were longer and thinner than those at 30 C. The fatty acid composition changed substantially upon growth at 40 C. yielding a distribution with a higher ratio of: i) saturated to unsaturated fatty acids and; ii) longer chain unsaturated fatty acids. Furthermore, the pattern of membrane proteins as determined by sodium dodecyl sulfate electrophoresis was distinctly different. The functional changes were typified by photosynthetic rates which were approximately half those of the 30 C grown cells. A number of spectral parameters were also seen to change in 40 C. grown cells: absorption spectra indicated a higher phycocyanin : chlorophyll ratio. Low temperature fluorescence spectra were consistent with a lowered efficiency of energy transfer from phycocyanin to chlorophyll. It is suggested that the fatty acid changes at 40 C. yield a more fluid membrane which is responsible for the functional alterations. The modification of phycocyanin. chlorophyll ratios, as well as the appearance of P750, is discussed with respect to membrane fluidity.
INFLUENCE OF TRICHOME LENGTH ON LINEAR TRANSLATION INOSCILLATORIA PRINCEPS(CYANOPHYCEAE)1
Authors: Halfen Lawrence N. , Halfen Mary E.
Published: April 2006

Motile trichomes ofOscillatoria princepsVoucher were examined to determine the relationship between trichome length and the ability to glide through hardened or viscous media. A minimum length for movement in solid media was found to be 0.1 mm in 0.5% agar (w/v).Viscous media tests revealed that coordinated movements through methyl cellulose media were not seen in trichomes 15–40 μ long at the viscosity employed. The minimum length motility increases with the viscosity of the medium and the gliding rates observed are greater in longer trihomes. These findings are discussed in relation to trichome surface area and the hypothesis that the motility system is restricted to lateral surfaces of the trichome.
CULTURE STUDY OF REPRODUCTIVE CYCLES AND SYSTEMATICA IN MOUGEOTIA TRANSEAUI (CHLOROPHYTA)1,2
Authors: Kennedy Frances G. R. , Hoshaw Robert W
Published: April 2006

Asexual and sexual reproductive cyries are described and illustrated for a cultured homothallic strain of Mougeotia transeaui Collins. Reproduction is by aplanospores and zygospores. Aplanospore formation precedes zygospore formation and continues longer with regreening of older cultures occurring regularly from precocious germination of aplanospores. Aplanospores typically form when most of the protoplast moves into the central swollen region of a cell and two new cross walls form to delimit an aplanosporangium. Conjugation is scalariform without the movement and fusion of well‐organized gametes. During zygospore maturation, three new cross walls form in the receptive gametangium and conjugation tube to produce a zygosporangium.
DIATOM COMMUNITY STRUCTURE: TAXONOMIC AND STATISTICAL ANALYSES OF A MISSISSIPPI SALT MARSH1
Authors: Sullivan Michael J.
Published: April 2006

Edaphic diatoms were collected on a seasonal basis from beneath five monospecific stands of spermatophytes on Graveline Bay Marsh (Mississippi) from 14 October 1976 through 21 June 1977. Of the 119 diatom taxa encountered. only seven were restricted to a single edaphic habitat, and five of these accounted for 17.2%of the individuals comprising the community associated withDistichlis spicata (L.) Greene. The single most abundant diatom wasNavicula tripunctata (Müll.) Bory, which accounted for 21.5%of all individuals counted during the study. Based on a 2‐way ANOVA of species diversity (H’) and the number of taxa in a sample, edaphic diatom community diversity was highest beneathD. spicataandSpartina patens (Ait.) Muhl., lowest beneathSp. alterniflora Loisel. and Juncus roemerianusScheele, and somewhat intermediate for theScirpus olneyiGray habitat. Structural differences between selected community pairs were quantified using a similarity index (SIMI) and the values generated were exceedingly variable. A multiple regression analysis revealed that structural differences amongst edaphic diatom communities were related to differences in elevation, far red light energy, ammonia nitrogen, soil moisture, and tentatively, height of the spermatophyte canopy.
VALVE AND BAND MORPHOLOGY OF SOME FRESHWATER DIATOMS I. FRAGILARIA CAPUCINA VAR. MESOLEPTA1,2
Authors: Hoagland Kyle D. , Rosowski James R.
Published: April 2006

Acid cleaned cells from clonal cultures of Fragilaria capucina var. mesolepta Rabh. were examined with light and scanning electron microscopy. Recently isolated cells are linear‐lanceolate in shape with a median constriction. After several transfers over 25 mo, cells exhibit size diminution resulting in small elliptically shaped valves. Adjacent valves are united to one another by interlocking marginal spines. Every valve has an apical pore field at each apex. A single labiate process is present infrequtently, appearing underdeveloped most often in size‐reduced cells. The girdle region consists of two cingula, each composed of a series of underlapping bands. Each pleura in the series is a discontinuous ring with a central ligula. A survey of past ultrastructure studies on the freshwater Fragilariaceae reveals that the occurrence of the apical pore field and labiate process are likely key characteristics for the family. The apical pore field of Diatoma, Asterionella and Tabellaria is positioned on the valve face, whereas the apical pore field of F. capucina var. mesolepta is located on the valve mantle, the girdle region of F. capucina var. mesolepta is basically similar to that of Gomphonema parvulum (Kütz.) Grun.
ALGAL CALCIFICATION IN SOME CODIACEAE (CHLOROPHYTA): ULTRASTRUCTURE AND LOCATION OF SKELETAL DEPOSITS1,2
Authors: Böhm Lothar , Fütterer Dieter , Kaminski Elfriede
Published: April 2006

The capitular filaments of Penicillus and Rhipocephalus consist of an inner tube containing the cytoplasm and an outer calcified sheath. The sheath originates at the cell wall and differentiates into several layers which form the outer filament wall. CaCO3 is deposited between organic layers within the sheath and is not in direct contact with the seawater. Pores within the sheath, usually uncalcified, may facilitate exchange of gases and solutes. The cytoplasm is characterized by vacuolar inclusions of calcium oxalate needles 50–150 μm long. A closed cortical surface is lacking. Udotea cyathiformis Dec. and U. conglutinata (Ellis & Sol.) Lam. are similar to Penicillus and Rhipocephalus, in addition showing some CaCO3 between filaments (ICS‐calcification). Udotea flabellum (Ellis & Sol.) Lam. is different as the filaments are profusely branched giving rise to a fully developed cortical surface. Pores and vacuolar calcium oxalate inclusions are absent. CaCO3 deposition occurs within cortical filaments in between layers of the filament wall and subcortically in intercellular spares (ICS). Cortex calcification shows primary and secondary deposits bearing some resemblance to sheath calcification and to coralline red algae. In Rhipocephalus phoenix (Ellis & Sol.) Kütz., Penicillus pyriformis A. &E. Gepp, U. cyathiformis and U. conglutinata CaCO3 is precipitated intracellularly within the sheath, in contrast to Halimeda and Cymopolia where it is deposited extracellularly in between filaments. U. flabellum takes an intermediate position showing both intra‐ and intercellular calcification. The sheath compartment volume is between 12.5 and 7500 μm3and 5–3 orders of magnitude smaller than the ICS‐compartment. Compartment size and location of CaCO3may bear on calcification mechanisms. One condition for such a mechanism may be restricted exchange of solutes (CO2, CO32‐, HCO3‐, O2, Co2+). Codiaceae; filament ultrastructure; Penicillus; Rhipocephalus; Udotea
ON SPECTRAL CONTROL OF PIGMENTATION IN ANACYSTIS NIDULANS (CYANOPHYCEAE)1,2
Authors: Myers Jack , Graham Jo‐Ruth , Wang Richard T.
Published: April 2006

Growth of Anacystis nidulans (Richt.) Drouet & Daily in wavelengths of light predominantly absorbed by chlorophyll a causes a dramatic lowering in chlorophyll content and in the chlorophylllphycocyanin ratio. A limit to the effect is reached in far red (680 nm) light where the ratio chlorophylllphycobilinogen falls to <0.3. A special water bath for culture tubes was illuminated by tungsten‐halogen lamps through far red (>650 nm)filters; it gave the same extreme pigment ratio together with a high specific growth rate of 2.5 day‐1. Compared with normally pigmented cells there are three features which accompany the low‐chlorophyll condition of far red light. At 677 nm relative quantum efficiency increases but action decreases. Synthesis of total pigment and total cell material in far red light also decreases. These observations suggest that the low chlorophyll response to far red light reflects an incompetence rather than an adaptation.