bluuebunny/crossref_metadata_2025_split huggingface dataset:
STUDIES ON THE AUTECOLOGY OF THE MARINE DIATOM THALASSIOSIRA NORDENSKIÖLDII CLEVE. 1. THE INFLUENCE OF DAYLENGTH, LIGHT INTENSITY, AND TEMPERATURE ON GROWTH1
Authors: Durbin Edward G. 
Published: August 2007

SUMMARYThe marine diatom Thalassiosira nordenskiöldii Clave was grown at 48 different combinations of daylength (9:15, 12:12, 15:9 LD), light intensity (0.011, 0.027, 0.066, 0.100 ly/min [g cal/cm2/min]), and temperature (0, 5, 10, 15 C). Growth occurred at all combinations of light and temperature except at 15 C at the highest light level. Maximum growth (K = 1.8 doublings/day) occurred at 10 C under the 15:9 LD cycle. At 15 C the maximum rate was 1.7 doublings/day but occurred at the shortest day‐length (9:15 LD). The maxima at 5 and 0 C were 1.32 and 0.67 doubling/day, respectively.At 0 C growth was similar over a wide range of light intensities (K = 0.6–0.65), with, maximum growth being attained at a much lower light intensity than at 5 C. Above 5 C there was a decrease in the light intensity at which maximum growth occurred and excessive light became inhibitory to growth. At 15 C the light intensity at which maximum growth occurred was greater with shorter day‐lengths. The temperature optimum was 10 C at 15:9 and 15 C at 9:15 LD.The chlorophyll a content of the cells was greatest under low light intensities and short daylengths, while temperature had a variable effect.The response of Thalassiosira in the laboratory contrasts with, its apparent preference for low temperatures in nature (0–5 C). The experiments suggest that the termination of the bloom of Thalassiosira in Narragansett Bay and elsewhere is not solely temperature dependent.
INTERSPECIFIC HYBRIDITY IN THE DESMID GENUS PLEUROTAENIUM1
Authors: Ling H. U. , Tyler P. A. 
Published: August 2007

SUMMARYThree desmid taxa, isolated from different parts of Australia, conform to the morphological taxa Pleurotaenium ehrenbergii, P. mamillatum, and P. coronatum. Use of successful zygospore formation between cells of mixed populations as an indication of ability to share a common gene pool shows that all 3 taxa are at least closely related and probably are members of the same biological species. Tentatively, we suggest synonymy of these taxa and urge the adoption of sexual criterion in delimiting desmid species.
NEW RECORDS OF ASCOPHYLLUM NODOSUM (L.) LE JOL. FROM THE WARMER PARTS OF THE ATLANTIC OCEAN1
Authors: John David M. 
Published: August 2007

SUMMARYFloating plants of Ascophyllum nodosum (L.) Le Jol. have been found for the first time at 00°47'S, 14°10'W to 01°21'S, 13°32'W. Populations of attached individuals do not occur below 40°N, although previous records of drift plants are known from further south. The plants found near the equator have probably arisen from attached populations in western Europe.
ACETATE METABOLISM BY WHOLE CELLS OF PHAEODACTYLUM TRICORNUTUM BOHLIN12
Authors: Cooksey Keith E. 
Published: August 2007

SUMMARYBoth morphological forms of Phaeodactylum tricornutum incorporated acetate in the light and in darkness. In the dark, the majority of the acetate was oxidized, probably by the tricarboxylic acid cycle. Although some CO2 was formed from acetate in the light, most acetate carbon was found in the cellular lipids. Acetate incorporation in the light was probably a result of both direct and indirect assimilation. The organism grew poorly on acetate in the light at a very low CO2 tension.
SEXUAL REPRODUCTION IN PANDORINA UNICOCCA1
Authors: Rayburn William R. 
Published: August 2007

SUMMARYThe effects of nutrients and light on sexual reproduction were investigated in 2 mating pairs of Pandorina unicoca. Strains 101–104 required nitrogen deficiency for sexual differentiation. Sulfur deficiency also appeared to be effective in evoking sexual differentiation. The time required for sexual differentiation of strains 103–104 after removal of KNO3 and MgSO from the medium was 24 hr. Addition of KNO3 and MgSO4 after 24hr did not reverse sexual differentiation. Light was required during the first 10–12 hr. Strains 105–106 did not require a period of sexual differentiation and, exhibited mating activity in the presence of nitrogen and sulfur in the medium. Both mating pairs required light for the mating response and calcium was necessary for zygote formation. The pH range for mating activity was determined.
THE SIGNIFICANCE OF REPRODUCTIVE AND SPORE GERMINATION CHARACTERISTICS TO THE SYSTEMATIC OF THE CORALLINACEAE: NONARTICULATED CORALLINE ALGAE12
Authors: Chihara Mitsuo 
Published: August 2007

SUMMARYThis paper deals with reproductive and spore germination characteristics to the systematics of the nonarticulated coralline algae. As can the articulated coralline algae, the nonarticulated coralline algae may also he divided into 2 groups on the basis of their yearly reproductive cycles, spore dimensions, and spore germination characteristics: the Lithophyllum group and the Lithothamnium group. These 2 groups are basically identical with the Amphiroa and Corallina groups of the articulated coralline algae, respectively, so far as these 3 characters are concerned. The grouping of these representatives of the Corallinaceae into 2 groups—Amphiroa—Lithophyllum and Corallina–Lithothamnium—coincides with a grouping based on the manner of connection between cells of adjacent filaments.
PHYSIOLOGICAL INVESTIGATIONS ON ALARIA ESCULENTA (L.) GREV. (LAMINARIALES). I. ELONGATION OF THE BLADE1,2,3
Authors: Buggeln Richard G. 
Published: August 2007

SUMMARYA seasonal rhythm in blade elongation rate was observed in Alaria esculenta. Maximum (3.0–3.6 cm/week) and minimum (0.5–1.0 cm/week) rates were recorded in June and September, respectively. Translocation of growth‐promoting metabolites occurs within the main blade and between the sporophylls and blade. Bidirectional flow of growth‐promoting metabolities within the stipe was demonstrated. Seasonal effects of nutrients (NO3‐ and PO43‐) and photoperiod on blade elongation were shown in long‐term laboratory experiments. Control of seasonal blade growth by exogenous and endogenous factors is discussed.
TWO SPECIES OF THE CHLOROPHYTE GENUS OSTREOBIUM FROM SKELETONS OF ATLANTIC AND CARIBBEAN REEF CORALS1,2
Authors: Lukas Karen J. 
Published: August 2007

SUMMARYTwo species of the siphonaceous chlorophyte Ostreobium inhabiting the aragonite skeletons of Atlantic and Caribbean reef corals were studied. Ostreobium quekettii Bornet & Flahault has been previously reported from these locations, but the species is here amended to include filament forms previously described under the name O. reineckei Bornet. Ostreobium constrictum sp. n. is described here for the first time. The 2 sympatric species are distinguished on the basis of filament morphology and chloroplast form.
THE ULTRASTRUCTURE OFDERBESIA TENUISSIMA(DE NOTARIS) CROUAN. I. ORGANIZATION OF THE GAMETOPHYTE PROTOPLAST, GAMETANGIUM, AND GAMETANGIAL PORE1,2,3
Authors: Wheeler Andrew E. , Page Joanna Z. 
Published: August 2007

SUMMARYThe fine structure of vegetative and reproductive gametophytes ofDerbesiatenuissima is described. Development of the gametangium and release of the gametes progress as follows: (1) In initial stages of gametangium formation, prior to 24 hr before gamete release, there is an accumulation and proliferation of nuclei, chloroplasts, and other organelles. (2) This is followed by separation of the gametangium from the rest of the plant by a gametangial membrane; segregation of organelles into gametes has begun by 12 hr before release and the process is completed by 2.5 hr before release. (3) Enzymatic wall dissolution of the pore area occurs between 2.5 and, 12 hr before normal lights‐on time. (4) The release mechanism appears to be an instantaneous light‐induced increase in lurgor pressure rupturing the weakened pore area, of the wall and causing a forcible expulsion of the gametes. (5) Following release, the pore is sealed by organellar debris and the gametangial membrane. Additional wall layers are presumed to be laid down internal to the plugged pore by the vegetative protoplasm which migrates into the area.
APPLICATION OF GAS‐LIQUID CHROMATOGRAPHY TO STUDY OF THE ENVELOPE LIPIDS OF HETEROCYSTS12
Authors: Lorch Steven K. , Wolk C. Peter 
Published: August 2007

SUMMARYGas‐liquid chromatography of algal extracts provides a sensitive assay for their content of 1‐(O‐α‐d‐glycopyranosyl)‐3, 25‐hexacosanediol, the principal glycolipid from the envelope of heterocysts of Anabaena cylindrica. Different patterns of lipids were found in the heterocysts of 5 species of Anabaena and Nostoc. Lipids with comparable chromatographic properties were detected in Gloeocapsa.
UPTAKE OF ORGANIC, COMPOUNDS BY TWO FACULTATIVELY HETEROTROPHIC MARINE CENTRIC DIATOMS1,2
Authors: White Alan W. 
Published: August 2007

SUMMARYGlucose and galactose uptake ability inCyclotella cryptica(clone WT‐1‐8) and glucose uptake ability inCoscinodiscussp. develop rapidly in the dark. Induction of sugar uptake ability in the dark does not require the presence of sugar in the medium. The sugars are taken up by carrier‐mediated systems. InC. crypticaglucose and galactose are probably taken up by the same system. The capacity of glucose uptake in this recently isolated clone ofC. crypticais nearly 5 times that of a previously studied clone (0‐3A). Other organic compounds, which by themselves do not support heterotrophic growth, can be taken up and respired by both diatoms at considerable rates compared, to glucose and galactose. Therefore, in nature, these diatoms may be able to utilize a variety of dissolved organic compounds as sources of intermediary metabolites and as respiratory substrates.
ISOLATION, GROWTH, AND PHYSIOLOGY OF ACIDOPHILIC CHLAMYDOMONADS1,2
Authors: Cassin Patricia Erlbaum 
Published: August 2007

SUMMARYA buffered, chelated, defined medium was developed for isolation and growth of acid‐bog flagellates and for physiological studies of bog chlamydomonads.Hydrogen ion tolerances of Chlamydomonas acidophila, C. sphagnophila 121 A, C. sphagnophila IU293, and, C. reinhardi were determined. Only C. acidophila grew at pH 2.0. It did not grow at pH 7.0 or 8.0 as did the other chlamydomonads tested. Liver fraction “L” and Fe permitted growth of C. acidophila at pH 2.0 equal to control growth at pH 5.0. Neither C. sphagnopliila 121A nor C. reinhardi grew at pH 2.0 with these additions. Hydrogen ion seems to be excluded from the cell interior of acid‐tolerant species. They remained green (ie, pheophytinization did not occur) when cultured below pH 5.0. C. acidophila grew in the dark with glucose as sole source of carbon and energy. Acetate, glycolate, and glyoxylate were assimilated in the dark if glucose was also present. C. sphagnophila 121A did not grow in the dark on any of the 51 organic carbon compounds tested. C. acidophila and C. sphagnophila 121A seem promising tools for determining biochemical mechanisms responsible for differences in H+ tolerances. Presumably specialized cell walls or membranes are involved.
A COMPARATIVE STUDY OF CELL DIVISION INTRICHOSARCINA POLYMORPHAANDPSEUDENDOCLONIUM BASILIENSE(CHLOROPHYCEAE)1
Authors: Mattox Karl R. , Stewart Kenneth D. 
Published: August 2007

SUMMARYPseudendoclonium basilienseandTrichosarcina polymorphaare essentially identical with regard to the fine structural details of cell division even though one was previously classified in the Chaetophorales and the other in the Ulvales. Cell division in the 2 genera is also shown to be like that inUlva,as previously suggested might be the case. The combination of mitotic and cytokinetic characteristics common to the 3 genera is distinctive: (1) precocious development of a thick cleavage furrow, (2) centrioles distinctly lateral to polar fenestrae, (3) collapse of the interzonal spindle at telophase, and. (4) a cleavage furrow not associated with microtubules. It is suggested that features of vegetative cell division presently provide the best, characteristics for defining the Ulvaceae and that the use of growth habit should be abandoned. Despite the fact that a phycoplast is not present, in these algae, it is concluded that their affinities lie with genera that do possess a phycoplast.
BENTHIC ALGAE OF SOUTHERN BAFFIN ISLAND. III. EPILITHIC AND EPIPHYTIC COMMUNITIES1
Authors: Moore J. W. 
Published: August 2007

SUMMARYBlue‐green algae–mainly Aphanocapsa pulchra (Kz.) Rabh., Oscillatoria tenuis Ag., Schizothrix muelleri Naeg., and Lyngbyn spp.—were predominant, in the epilithic communities of Baffin Island rivers and lakes during 1972, usually accounting for more than 90% by numbers and volume of the total flora. Diatoms were only important early in the growing season (June) with Achnanthes marginulata Grun., A. kriegeri Krasske, and Tabellaria flocculosa (Roth) Kz. being most common. Standing crop in one river increased from near 0 in June to 6.0 × 104 cells/cm2 (2.2 × 108μ3/cm2) in July and back to near 0 again by October. Low levels of nitrate nitrogen probably limited algal numbers, while flooding, light, and grazing by herbivores appeared to have little effect. Changes in algal standing crop in the lakes followed much the same pattern as outlined above. However, the maximum amount of algae was considerably greater than that recorded from the rivers, reflecting the greater availability of nutrients. Lyngbya nana Tild. was the main algal species attached, to filaments of Mougeotia sp., reaching greatest development (5.0 × 104 filaments/cm2) during September. On the other hand, diatoms–mainly Ceratoneis arcus Kz. and varieties, Fragilaria spp., and Synedra spp.–were predominant in the community floating among the filaments with maximum standing crop (64.48 × 106 cells/g dry weight of Mougeotia) occurring in July. The small diameter of the Mougeotia filaments was probably the main factor limiting the size of both the attached and free‐floating communities.
UPTAKE AND RELEASE OF METHYLMERCURY‐203 BYCLADOPHORA GLOMERATA1
Authors: Burkett Robert D. 
Published: August 2007

SUMMARYCladophora glomeratawas exposed to CH3203HgCl at concentrations of 10, 50, and 100 μg/liter of water. Formalin‐killed alga was exposed to a concentration of 50 μg CH3203HgCl/liter. Uptake was monitored at 2 and 12 hr, and days 1, 2, 4, 8, and 16. At the end of this period, theCladophorawas placed in uncontaminated water, and release of methylmercury was monitored at 1, 2, 4, 8, and 16 days. Sorption occurred at all concentrations, and the live algal material accumulated more methylmercury than the dead alga, at equal exposure concentrations. Accumulation of methylmercury by the liveCladophorapeaked on or near the second day for all exposure concentrations, suggesting that the uptake rate was independent of methylmercury concentration in the water. Uptake was greatest at the 50 μg/liter exposure. Desorption was nominal during the 16‐day release period. The mechanisms of methylmercury uptake byCladophoraare discussed.
A SEAWATER MEDIUM FOR DINOFLAGELLATES AND THE NUTRITION OF CACHONINA NIEI1
Authors: R. Loeblich Alfred 
Published: August 2007

SUMMARYTwo media have been devised: an enriched seawater medium for culture of dinoflagellates and a defined medium for rapid growth of the dinoflagellate Cachonina niei. A wide range in salinity (10.23–42.38 g/liter NaCl) is tolerated by C. niei. Below 0.6 g/liter MgSO4, 0.19 g/liter KCl, and 0.22 g/liter CaCl2, the generation time greatly increases. Increase in MgSO4 to 7.22 g/liter, KCl to 1.12 g/liter or CaCl2 to 2.22 g/liter has little effect on generation time. The temperature optimum is 19–23 C. Saturating light intensity for growth is 1000 ft‐c and for photosynthesis (determined manometrically) is slightly less than 2000 ft‐c. Cachonina niei requires B12 and thiamin. Neither silicate nor its competitive inhibitor germanate affects generation time or cell yield indicating silicon is not required. Of a variety of buffers tested, Tris is the best. Optimal growth occurs at pHs of 7.5–8.3. Glycerol is inhibitory and does not support dark growth.
THE ULTRASTRUCTURE OF MULTILAYERED STRUCTURES ASSOCIATED WITH FLAGELLAR BASES IN MOTILE CELLS OFTRENTEPOHLIA AUREA1
Authors: Graham Linda E. , McBride Gordon E. 
Published: August 2007

SUMMARYAn ultrastructural study of motile cell development in the green algaTrentepohlia aureahas revealed the presence of multilayered structures (MLS) associated With flagellar bases. These MLS are ultrastructurally similar to MLS described in pteridophyte and bryophyte sperm and in the zoospore of the green algaeColeochaeteandKlebsormidium.However, 2 MLS are found in each biflagellate motile cell ofT. aurea, while other previously described MLS occur singly in biflagellate motile cells. In addition, the MLS ofT. aureaconsist of fewer microtubules and are structurally simpler than most other MLS described. The MLS ofTrentepohliamay represent a stage in the evolutionary development of the MLS of land plants. The presence or absence of the MLS in motile cells of green algae may be a useful character in phylogenetic studies.
CHEMOTAXONOMY IN MARINE ALGAE: CHEMICAL SEPARATION OF SOME LAURENCIA SPECIES (RHODOPHYTA) FROM THE GULF OF CALIFORNIA1
Authors: Fenical William , Norris James N. 
Published: August 2007

SUMMARYSpecies separation in the genus Laurencia (Rhodomelaceae, Rhodophyta) is complicated by the high degree of morphological variation within the species. Chemical investigations on a worldwide basis of over 15 species indicate that 1 or more of the halogenated natural products synthesized by Laurencia are unique to each species. Our chemical investigations of Laurencia pacifica, as presently understood from the Gulf of California, indicate that more than 1 species had been included under this name. Thin layer chromatographic (TLC) comparisons of the halogenated components of 3 recognizable forms of “L. pacifica” were completed. The results revealed 3 distinct forms, with halogenated products unique to each form. In each form the observed chemical characters had been previously isolated and identified and could now be positively assigned to their algal source. Comparisons were also conducted with L. pacifica Kylin (1941) from the type locality of the species, La Jolla, California, and revealed that it contained another halogenated product different from those isolated from the Gulf species. We conclude that 3 species of Laurencia have been elucidated in the Gulf of California and these are separate from L. pacifica Kylin. Each species can be distinguished by its characteristic array of halogenated compounds. Comparative thin layer chromatography of the lipid components of morphologically similar Laurencia species should prove to be a useful new taxonomic aid.
THE DISTRIBUTION OF PHOTOSYNTHATE IN ASCOPHYLLUM NODOSUM AS IT RELATES TO EPIPHYTIC POLYSIPHONIA LANOSA12
Authors: Harlin Marilyn M. , Craigie J. S. 
Published: August 2007

SUMMARYThe brown alga Ascophyllum nodosum is not a major source of organic carbon for its epiphytic red alga Polysiphonia lanosa. Plants pulse‐labeled for 24–25 hr with NaH14CO3 were examined for exudation and translocation. The maximum amount of radioactive carbon compounds lost from A. nodosum during this experimental period was less than 0.3% of the total 14C fixed by the alga, and of this amount, only 5% could, have moved through the frond. The remaining fraction of the 14C lost from the thallus was released into the water.The total exudate from A. nodosum was collected for 1 week in a series of flasks of filtered seawater changed at 12‐hr intervals corresponding with the beginning of the light and dark periods, respectively. During 7 days at 15 C only 1.5% of the total 14C originally fixed had been released as radioactive organic carbon, whereas at 5 C, 0.6% of the total 14C fixed was found in the medium. No significant difference in the rate of exudation of organic 14C was observed in light or darkness. After fractionation of the exudate it was found that only 10% of the radioactivity in these exudates was composed of organic acids or amino acids. P. lanosa, on the other hand, is perfectly capable of fixing its own carbon. The photosynthetic rates measured by H14CO3 uptake confirm the observations of Bidwell: 3.96 mg CO2/g/hr (0.09 m mole/g/hr).
FINE STRUCTURE OF CELL DIVISION INPYRAMIMONAS PARKEAENORRIS AND PEARSON (CHLOROPHYTA, PRASINOPHYCEAE)1
Authors: Pearson Barbara R. , Norris Richard E. 
Published: August 2007

SUMMARYCell division inPyramimonas parkeaeis described and compared with some other green algae. The first indication of mitosis is division of the chloroplast, accompanied by growth of a prominent microbody, followed by replication of the 4 basal bodies. Also closely timed with this is the replication of the Golgi and other components of the basal body complex. Two basal body complexes separate, each taking a position at either pole of the nucleus which has migrated to a characteristic position just beneath the plasmalemma of a broadened and flattened flagellar pit. Cytokinesis is accomplished by the fusion of ducts and vesicles with the simultaneous release of scales to the newly formed exterior. Cells swim throughout division.
THE STATOSPORE OF DINOBRYON DIVERGENS IMHOF: FORMATION AND GERMINATION IN A SUBARCTIC LAKE1
Authors: Sheath Robert G. , Hellebust Johan A. , Sawa Takashi 
Published: August 2007

SUMMARYThe population dynamics and the sequences of statospore development and germination of Dinobryon divergens from a shallow subarctic lake were examined. D. divergens showed a sharp increase in the vegetative cell population between June 19 and July 3, 1973, followed by a rapid formation of statospores from June 26 to July 3. Shortly after spore production, this species decreased sharply to an insignificant level in the phytoplankton. Statospore formation to as initialed by migration of the monad cell to the lorica mouth and proceeded by rounding up of the cytoplasm. There was then an unequal cleavage, silica wall formation around the larger portion of the cytoplasm including the nucleus and disintegration of the extracystic cytoplasm after development of the plug. The statospore was uninucleate throughout its development, and it was concluded that spore formation occurred asexually. Germination of statospores was observed in periphyton samples at depths of 20 and 80 cm on July 20–21, 1973 and in the sediments earlier the following year. During germination a cellulose chamber was produced from the pore of the statospore, followed, by cleavage of the cytoplasm within the spore and migration of approximately 4 daughter protoplasts into the cellulose chamber from which they eventually escaped. The present study proposes that chrysophycean statospores arising asexually and endogenously should be recognized as separate entities from those formed isogamously and autogamously but not necessarily endogenously. The latter statospores resulting from the sexual process have been given the term zygospore.
HYMENOMONAS CORONATA SP. NOV., A NEW COCCOLITHOPHORID FROM THE TEXAS COAST1,2
Authors: Mills Jimmy T. 
Published: August 2007

SUMMARYA new species of Hymenomonas (H. coronata) has been isolated from the Texas coast, grown in axenic culture, and examined by both light and electron microscopy. Certain cultural and ultrastructural observations are presented. This alga has several haptophycean characteristics, although a definite haptonema has not been observed. Similarities to other members of the genus are evident, such us type and shape of coccoliths and pyrenoid‐chloroplast morphology.