bluuebunny/crossref_metadata_2025 huggingface dataset:
STEADY STATE GROWTH OF PHYTOPLANKTON IN CONTINUOUS CULTURE: COMPARISON OF INTERNAL AND EXTERNAL NUTRIENT EQUATIONS1,2
Authors: Goldman Joel C.
Published: August 2007

Previously, there have been conflicts over whether external or internal nutrient concentrations control phytoplankton growth rates at steady state in continuous culture. To experimentally demonstrate that both equations equally describe steady state growth, continuous culture studies with phosphorus‐limited growth of the chrysophyte Monochrysis lutheri Droop were carried out over the entire growth rate region up to biomass washout. Data were examined using both the Monod and Droop equations, and, even though there were significant variations in the yield coefficient with growth rate, the data fit both equations reasonably well. Because of their relative simplicity, the Droop equation and an equation combining both the Monod and Droop equations are better suited for expressing kinetic data than the Monod equation. It is crucial, though, that the criteria necessary to achieve steady state be fulfilled.
AN ABERRANT CHRYSOPHYCEAN ALGA PELAGOCOCCUS SUBVIRIDIS GEN. NOV. ET SP. NOV. FROM THE NORTH PACIFIC OCEAN1,2
Authors: Lewin Joyce , Norris Richard E. , Jeffrey S. W. , Pearson Barbara E.
Published: August 2007

A description and Latin diagnosis of the new genus and species Pelagococcus subviridis Norris is presented. Pale green, spherical cells appeared in enrichment cultures initiated from water samples collected at stations between 132°W and 175°W and between 45°N and 50°N in the North Pacific Ocean. The alga is placed in the Chrysophyceae based on organelle fine structure, and presence of chlorophylls a and c, diatoxanthin, diadinoxanthin and two fucoxanthin‐like pigments. There are a number of atypical features however; the two fucoxanthin‐like pigments differ from true fucoxanthin; there is only chlorophyll c2 (not C1+ c2); probably mostly a, not β‐carotene; half of the chlorophyll a is in the form of chlorophyllide a.
CONTINUOUS FLOW CULTURE OF BENTHIC DIATOMS AND ITS APPLICATION TO BIOASSAY1,2
Authors: Lin C. Kwei
Published: August 2007

The benthic diatom,Navicula seminulumvar.hustedtiiPatr, was isolated from the field and studied in laboratory cultures. Experiments were conducted to determine the suitability of Millipore membranes and solidified agar substrate for diatom colonization under continuous flow conditions. Diatom colonization showed large variation and low reproducibility on Millipore membranes of different materials and pore sizes. Solidified agar substrate supported stable and reproducible colonization and is nutritionally neutral, translucent, homogeneous and easy to sample. The diatom colonization process on agar substrate involved four growth phases: i) pioneer; ii) exponential; iii) steady state; and, iv) vanishing. The culture system was also used in bioassay, testing the toxic effect of copper on the growth of benthic diatoms. The proposed method provides a useful means for studying autecology of benthic diatoms as well as for bioassay work.
EFFECT OF BLUE‐GREEN LIGHT ON PHOTOSYNTHETIC PIGMENTS AND CHLOROPLAST STRUCTURE IN THE MARINE DIATOM STEPHANOPYXIS TURRIS1
Authors: Jeffrey S. W. , Vesk Maret
Published: August 2007

Blue‐green light increased the chlorophyll concentration and chloroplast number of cells of Stephanopyxis turris (Grev.) Ralfs, compared to white light controls. Light fields for growth were 400 μW·cm−2 (12:12 LD cycles). Chlorophyll increased up to 100%/cell, but no change in the ratio of chlorophylls to major carotenoids occurred. The effect was, therefore, not that of complementary chromatic adaptation. At the same time, blue‐green light enhanced the photosynthetic fixation of CO2. At the ultrastructure level, an increase in, and rearrangement of, the thylakoid system occurred.
EFFECT OF BLUE‐GREEN LIGHT ON PHOTOSYNTHETIC PIGMENTS AND CHLOROPLAST STRUCTURE IN UNICELLULAR MARINE ALGAE FROM SIX CLASSES1
Authors: Vesk Maret , Jeffrey S. W.
Published: August 2007

The photosynthetic pigments of 17 species of unicellular marine algae grown in white and blue‐green light were examined. Blue‐green light (400 μW·cm−2; 12:12 LD cycle) caused major chlorophyll increases (55–146%) in five diatoms, one dinoflagellate and one cryptomonad; minor chlorophyll increases (17–39%) in two diatoms, two dinoflagellates, one prymnesiophyte (haptophyte), one chrysophyte and one chlorophyte; and no chlorophyll increase in two diatoms and one pyrmnesiophyte (haptophyte). The relative proportions of major chlorophylls and carotenoids did not change, but in six of eight species tested small increases in the concentration of chlorophyll c occurred. Blue‐green light caused a small increase in the concentration of phycoerythrin relative to chlorophyll a in the cryptomonad. A larger number of thylakoids per chloroplast were observed in six species grown in blue‐green light compared to white light controls. The ultrastructure changes observed depended not only on the magnitude of the chlorophyll increase but also on the architecture of the chloroplast.
EFFECT OF NITROGEN SOURCE ON PLATYMONAS (CHLOROPHYTA) CELL COMPOSITION AND AMINO ACID UPTAKE RATES1
Authors: Wheeler Patricia A.
Published: August 2007

The effect of nitrogen source (nitrate, ammonia and/or amino acids) on cell composition and amino acid uptake rates was examined. Substantial levels of free amino acids accumulated intracellularly with all nitrogen sources used. Ammonia accumulated only when provided in the medium. The presence of ammonia in the medium decreased the intracellular accumulation of free amino acids, especially arginine. Amino acid uptake rates were suppressed by the presence of excess nitrogen, especially ammonia. However, the suppression of uptake did not show any particular relation to the nitrogenous cell composition.
HETEROTROPHIC NUTRITION AND ITS EFFECTS ON CHLOROPHYLL SYNTHESIS INGOLENKINIA(CHLOROPHYCEAE)1
Authors: Ellis Richard J.
Published: August 2007

Glucose and sodium acetate are the only carbon sources able to support heterotrophic growth ofGolenkinia minutissimaIyengar & Balakrishnan. Heterotrophic growth is maximal at a concentration range of 20–40 mM of either carbon source; however, growth is significantly more rapid and higher yields are obtained with acetate. Mannose is toxic but this effect is competitively reduced by the presence of glucose. The inhibitory action of acetate on chlorophyll synthesis is unaffected by 20 mM glucose, indicating that this inhibition is not related to the absence of glucose.
FEULGEN MICROSPECTROPHOTOMETRIC INVESTIGATION OF THE LIFE HISTORY OF FRITSCHIELLA TUBEROSA(CHLOROPHYCEAE)1
Authors: Hopkins Archibald W.
Published: August 2007

A Feulgen microspectrophotometric analysis of successive generations of Fritschiella tuberosa Iyengar revealed an asexual repeating of one generation rather than an obligate alternation of isomorphic generations as previously described. F. tuberosa regularly reproduces asexually by the release of one quadriflagellate zoospore produced/cell in all parts of the upright and prostrate portions of the thallus. In the vegetative thalli, nuclei in the G1 (pre‐synthesis), synthesis, and G2 (post‐synthesis) phases of the mitotic cycle are all well‐represented.
HISTOCHEMICAL STUDIES OF THE EXTRACELLULAR CARBOHYDRATE OF COLACIUM MUCRONATUM (EUGLENOPHYCEAE)1
Authors: Willey Ruth L. , Ward Kathleen , Russin William , Wibel Ronald
Published: August 2007

The stalk of Colacium mucronatum Bourr. & Chad. is composed primarily of a cylindrical shaft with a lightly staining inner core and diffuse peripheral cortex. The shaft and cortex arise from a ring‐shaped region around the canal opening whereas the core appears continuous with the canal which may be associated with initial cell attachment. All parts of the stalk, as well as the lining and contents of the reservoir, canal and flagellum exhibit stain reactions associated with neutral or mildly acidic carbohydrate with widely spaced anionic groups in low concentration.
IMMUNOFLUORESCENCE FOR AUTECOLOGICAL STUDY OF A UNICELLULAR BLUEGREEN ALGA12
Authors: Fliermans C. B. , Schmidt E. L.
Published: August 2007

Fluorescent antibody (FA) preparations were developed and tested as an approach to recognition and enumeration of a specific unicellular bluegreen alga in a natural ecosystem. Antibodies made against an axenic culture of Synechococcus cedrorum Näg. gave a high agglutination titer and an excellent homologous staining reaction. Antibody specificity was tested with 28 heterologous cultures of bluegreen algae, known cultures of chemoautotrophic bacteria and heterotrophic bacteria, and randomly selected unknown bacteria from soil, sewage and aquatic habitats. FA staining of bluegreen algae was restricted to S. cedrorum and six heterologous isolates, all indistinguishable microscopically from S. cedrorum. The ability to enumerate S. cedrorum FA‐reactive cells in nature was demonstrated with data on population densities for samples taken from water columns of stratified holomictic lakes in northcentral Minnesota.
NITRATE REDUCTASE MUTANTS IN EUDORINA ELEGANS (CHLOROPHYCEAE)1
Authors: Toby Anne L. , Kemp C. Lindley
Published: August 2007

Three nitrate reductase mutants were independently isolated and characterized in the colonial alga, Eudorina elegans Ehrenberg. nar‐1 is a leaky mutant, deficient in the production of nitrate reductase. nar‐2 and nar‐3 both lack the ability to produce nitrate reductase. However, nar‐2 grows and nar‐3 does not grow when hypoxanthine is the sole nitrogen source. The specific activity of the next enzyme, in the pathway, nitrite reductase is increased in nar‐3 when compared to wild‐type, nar‐1 and nar‐2.
INVERSION IN VOLVOX (CHLOROPHYCEAE)1
Authors: Kelland John Laurence
Published: August 2007

The asexual embryos of Volvox turn themselves inside out (invert) during development. Data presented indicate that inversion of the embryos is the result of several simple cellular shape changes, coordinated in space and time. Using whole embryos, cell groups and individual embryonic cells isolated by watchmaker's forceps and pressure on the coverslip, it was shown that the phialopore (opening) enlargement and concurrent stretching of the border cells is due to a constriction formed at the equator. However, if the posterior hemisphere is removed, this constriction no longer effects the expansion of the phialopore (which is in the anterior hemisphere) because the equatorial region is no longer anchored and has no base to support the outwardly directed force against the phialopore cells. If the posterior hemisphere is isolated several hours before inversion, the opening resulting from the incision acts as a “phialopore” and the direction of inversion is reversed. Individual cells and cells in groups undergo the same shape changes as corresponding cells in an intact embryo during inversion. This suggests that these cellular deformations are autonomous and inversion is a result of them.
ECOLOGY AND NATURAL HISTORY OF IRIDAEA CORDATA (GIGARTINALES, RHODOPHYTA) GROWTH1
Authors: Hansen Judith E.
Published: August 2007

The in situ growth, maturation and senescence, of central California Iridaea cordata (Turner) Bory was studied. This ontogenetic progression was quantified by measuring development and growth of: i) individually tagged blades, and ii) populations of blades within cumulative (1‐yr duration) and seasonal experimental plots. Greatest growth and longest life span were exhibited by winter‐spring initiated blades, and were correlated with a rapid increase, in irradiance, but not with either seawater temperature or nutrients. Tagging studies showed that reproductive maturation and senescence of blades occurred throughout the year, irrespective of date tagged, growth rate or size. Moreover, the majority of blades continued to elongate following maturation, and some matured within 3 mo of initiation at all seasons but winter. At the population level maturation took place primarily during summer‐autumn when 90 ±2% of the population was mature. The majority of the population senesces or “dies back” during autumn‐winter. It is concluded that in situ, the blades are derived almost totally via vegetative means involving perennation. This indirectly suggests that sexual reproduction or the success of sporeling development are marginal. Additionally, the species is perennial with annually deciduous blades, characterized by both rapid growth and maturation.
COMPARISON OF ATTACHED DIATOM COMMUNITIES ON NATURAL AND ARTIFICIAL SUBSTRATES1
Authors: Siver Peter A.
Published: August 2007

A study of attached diatom communities on artificial and natural substrates was conducted in Wheelwright Pond, New Hampshire, during 1975. There were differences in the species composition growing on artificial glass slides and natural substrates. The slides favored the accumulation of Achnanthes minutissima Kütz. and decreased the relative abundance of Eunotia incisa W. Sm. ex. Greg. and Cocconeis placentula v. euglypta (Ehr.) Cleve. Large growths of planktonic species were also noted on the slides. Compositional differences between slides positioned at 15–30 cm (upper) and 1 m (lower) from the surface of the water were minimal. A similar community composition of periphytic diatoms was found on five aquatic macrophytes.
ADAPTATION OF STYROFOAM SUBSTRATE TO BENTHIC ALGAL PRODUCTIVITY STUDIES IN LAKE TAHOE, CALIFORNIA‐NEVADA1
Authors: Flint R. Warren , Richards Robert C. , Goldman Charles R.
Published: August 2007

A routine sampling technique has been developed using artificial styrofoam substrate to estimate benthic algal productivity in the littoral zone of lakes. Estimation of maximum carbon fixed in Lake Tahoe ranged from 11.1 mg C·m−2· day−1 at 0.5 m to 17.1 mg C·m−2· day−1 at 1.0 m. Estimates were made for communities composed of both diatom and green algal populations in water between 0.5 and 3.0 m. Maximum productivity occurred between 1–2 m. The technique developed can give comparable estimates of productivity if adequate replication is undertaken to decrease problems associated with periphytic heterogeneity.
TWO NEW SPECIES OF PSEUDOKEPHYRION (CHRYSOPHYCEAE) IN THE PLANKTON OF A LAKE1
Authors: Nicholls Kenneth H.
Published: August 2007

Two new species of Pseudokephyrion are described from Little Aurora Lake, Ontario, Canada. The distribution of both P. taeniatum sp. nov. and P. auroreum sp. nov. is restricted, for reasons which are not clear; neither species was found in samples from lakes adjacent to Little Aurora Lake. All lakes in the vicinity are very dilute, oligotrophic and acidic.
EPIPELIC AND EPILITHIC DIATOM ASSEMBLAGES IN MONTEZUMA WELL NATIONAL MONUMENT, ARIZONA1
Authors: Czarnecki David B.
Published: August 2007

Epipelic and epilithic diatom assemblages in Montezuma Well National Monument, Arizona, were identified and analyzed by H' (species diversity), species number, J' (evenness), relative abundance, SIMI (similarity index), and DI (dissimilarity index) values. The epipelic assemblage was found to be a tri‐dominant association ofCyclotella pseudostelligera f. parvaCzar. & Blinn,Cocconeis placentulavar.lineata(Ehr.) V.H. andAchnanthes linearis(W. Sm.) Grun. The epilithic assemblage was a tri‐dominant association ofRhoicosphenia curvata(Kütz.) Grun. ex Rabh.,Cy. Pseudostelligera f. parvaandSynedra ulna(Nitz.) Ehr. Both associations persisted throughout the year. Of the 83 taxa observed, 51 were common to both assemblages, 24 were restricted to the epipelon, and 8 were restricted to the epilithon. On a yearly basis, the epipelic assemblage exhibited less diversity (H') than the epilithon, even though the latter exhibited fewer taxa. The use of mean diversity values was also determined to be unacceptable.Cy. Pseudostelligera f. parvaandS. ulnaappeared more abundant under high light intensity and duration,Fragilaria construensvar.venter(Ehr.) Grun. favored low light intensity and duration, whereasA. linearis, R. curvataandCo. placentulavar.lineatawere tolerant of a variety of intensities and durations. On a yearly basis, both assemblages exhibited slight similarity (SIMI, DI). The use of SIMI values for comparing assemblages with few highly abundant taxa was determined to be unacceptable and under these conditions, the use of DI was recommended.
INTERACTION (ALLELOPATHY) BETWEEN MARINE DIATOMS: THALASSIOSIRA PSEUDONANA AND PHAEODACTYLUM TRICORNUTUM1
Authors: Sharp Jonathan H. , Underhill Peter A. , Hughes David J.
Published: August 2007

Two marine diatoms were studied singly and in mixed culture. Thalassiosira pseudonana (Hust.) Hade & Heimdal was capable of a higher growth rate (μmax) than Phaeodactylum tricornutum Bohlin. In two‐species batch cultures P. tricornutum took over in the latter portion of the exponential phase, possibly due to allelopathy. The filtrate from this species caused an initial lag phase and a reduced terminal population density for T. pseudonana. Two‐species continuous cultures showed verification of these interactions. At high dilution rate (i.e., high growth rate) P. tricornutum washed out when added at low density, whereas T. pseudonana maintained constant cell density. However, when sufficient density of P. tricornutum was added as a contaminant, both species washed out. At a lower dilution rate P. tricornutum increased in density when added and eventually reached a stable population; T. pseudonana then washed out.
MITOSIS AND CLEAVAGE DURING ZOOSPOROGENESIS IN SEVERAL COCCOID GREEN ALGAE1
Authors: Deason Temd R. , O'Kelley Joseph C.
Published: August 2007

The fine structure of mitosis and cleavage inAxilosphaera vegetataCox & Deason,Chlorococcum echinozygotumStarr,Chlorosarcinopsis eremiChantanachat&Bold,Nautococcus mammilatusKorshikoff,N. terrestrisArchibald,N. solutaArchibald,Neospongiococcum solitariumDeason, andTetracystis aeriaBrown & Bold was observed. All possess a phycoplast, but differences in basal body position during mitosis were observed.Nautococcus mammilatusdiffers from the others as protoplast rotation occurs in many cells prior to cleavage.
SEASONAL CYCLING OF ALGAL NUTRIENT LIMITATION IN CHAUTAUQUA LAKE, NEW YORK1
Authors: Storch Thomas A. , Dietrich Geoffrey A.
Published: August 2007

Algal nutrient enrichment bioassays were conducted between May 1975 and August 1978 using water samples collected from Chautauqua Lake, New York. Photosynthetic fixation rates of natural phytoplankton assemblages were enhanced by additions of phosphorus and nitrogen, although enrichment with other nutrients had no significant stimulatory effect on algal photosynthesis. Whereas phosphorus stimulated in spring and early summer, both nitrogen and phosphorus enhanced photosynthesis in midsummer and fall. Relative to the effect of phosphorus enrichment, enhancement of photosynthesis by nitrogen during the summer and fall was highest in the northern part of the lake. During the period of ice cover, photosynthesis did not appear to be limited by nutrients in that nutrient additions (P, N, Si, C, Fe, trace metals) did not enhance fixation rates. Observed temporal fluctuations in the response of the algae to P and N correlated with changes in the lake water N:P ratio as well as with temporal changes in dissolved orthophosphate and nitrate‐nitrite nitrogen. The N:P ratio decreased drastically in the summer and remained at ca. 10 or less through mid‐fall, suggesting that N concentrations were inadequate for the non‐N‐fixing phytoplankton. Studies over 3 yr indicate that states of P and N limitation undergo time‐space fluctuations that occur in a cyclic pattern in the surface waters of Chautauqua Lake.
RECYCLING OF METABOLIZED IRON BY THE MARINE DINOFLAGELLATE AMPHIDINIUM CARTERAE1
Authors: Frey Bruce E. , Small Lawrence F.
Published: August 2007

Senescent, iron‐limited cultures of Amphidinium carterae Hulburt were used to detect the presence of iron made available for phytoplankton growth by recycling of metabolized iron from disrupted cells. Both physical disruption of cells and physical disruption plus exposure to a low pH were tested. The test cultures remained viable over long periods of time, and were stimulated to full growth by the addition of Fe, but not by the addition of any other nutrients. Simple physical disruption of cells caused only a very slow release of available Fe, while disruption of cells plus exposure to a low pH resulted in a rapid release of available Fe. It is suggested that the digestive processes of herbivores are instrumental in the rapid regeneration of Fe as a nutrient available for phytoplankton growth.
ULTRASTRUCTURE OF TETRASPOROGENESIS INPALMARIA PALMATA(RHODOPHYTA)1
Authors: Pueschel Curt M.
Published: August 2007

The tetrasporangial initial inPalmaria palmata(L.) O. Kuntze (formerlyRhodymenia palmata(L.) Greville) arises from a cortex cell which enlarges and deposits a protein‐rich wall layer. This cell undergoes mitosis to form a tetrasporocyte and a stalk cell. Synaptonemal complexes are formed in the sporocyte nucleus while in the cytoplasm floridean starch is deposited in association with ER or with particles presumed to be ribosomes. Microbody‐like structures become numerous between the nuclear envelope and perinuclear ER, and clusters of non‐membranous, spherical structures also are associated with the nucleus. Chromatin condensation is reversed following pachytene and a prolonged diffuse stage ensues, when dictyosomes and ER produce vesicles which deposit mucilage rich in sulfated and acidic polysaccharides around the tetrasporocyte. A conspicuous lenticular thickening of the mucilage sheath develops at the apical end of the sporangium. Dictyosomes are frequently associated with mitochondria which may be associated with chloroplasts. Following nuclear divisions the tetrasporocyte is cleaved into four spores by sequentially initiated, but simultaneously completed periclinal and anticlinal furrows. When mucilage deposition ceases, the dictyosomes begin to produce vesicles with glycoprotein‐rich contents. These vesicles are abundant in released tetraspores, and they probably contain adhesive material aiding in the attachment of the liberated spores.
MORPHOLOGY OF THE SUBANTARCTIC RED ALGA CENACRUM SUBSUTUM GEN. ET SP. NOV. (RHODYMENIALES) FROM MACQUARIE ISLAND1
Authors: Richer Robert W. , Kraft Gerald T.
Published: August 2007

The red alga Cenacrum subsutum gen. et sp. nov. is described from material collected at Macquarie Island in the subantarctic between November 1977 and February 1978. The habit and carposporophyte development are similar to members of the family Rhodymeniaceae (Rhodymeniales), but certain vegetative features are unique. The frond is a variously incised or lobed foliose blade with hollow apices above and a medulla which becomes progressively filled basipetally with ingrowing rhizoidal filaments. Details of carpogonial branch, auxiliary cell, connecting cell and gonimoblast anatomy are given, as well as observations on the habitats and distribution of the species.
SEASONAL CHANGES IN STRUCTURE OF A SUBMERGED BLUEGREEN ALGAL/BACTERIAL COMMUNITY FROM A GEOTHERMAL HOTSPRING1
Authors: Fagerberg Wayne R. , Arnott Howard J.
Published: August 2007

The species (cytospecies) structure and seasonal dynamics of a thermophilic bluegreen algal/bacterial community from Mimbres, New Mexico are described. Using stereological techniques, several common quantitative ecological parameters (biomass, density, distribution measurements, Species Diversity Indices, importance values) were described for the community growing ca. 1 m beneath the water surface on the inner walls of a concrete cistern. Temperature and pH were relatively constant while water flow rates, duration and intensity of light showed seasonal variation. The total volume of the mat occupied by living organisms did not exceed 2% during the entire year. The remaining volume was occupied by gas and water bubble chambers, gelatinous matrix, empty tubes, mineral deposits, and water. The total biomass remained constant except during a period of severe, seasonal light reduction (November). Species Diversity Indices, density and importance values for the bluegreen algal and bacterial populations showed seasonal changes. The three dominant bluegreen algal cytospecies which represented the greatest amount of biomass alternated in their abundance on a seasonal basis while the three dominant bacterial cytospecies remained the same throughout the period of study. Although considerable season change occurred in the species structure of this community, the total living volume remained relatively constant with the major changes in the bluegreen algal populations. Many of the seasonal changes observed appear to correlate with seasonal changes in light intensity and duration.
FINE STRUCTURE OF MITOSIS AND CLEAVAGE IN FRIEDMANNIA ISRAELENSIS (CHLOROPHYCEAE: CHLOROSARCINACEAE)1
Authors: Deason Temd R. , Ryals Phillip E. , O'Kelley Joseph C. , Bullock Kenneth W.
Published: August 2007

Observations on the ultrastructure of Friedmannia israelensis Chantanachat & Bold revealed the presence of a phycoplast and zoospores with cruciate rootlets. During mitosis, the nuclear envelope partially disintegrates and the basal bodies remain at the cell surface on either side of the developing cleavage furrow. The events during mitosis and cleavage in Friedmannia resemble those reported in the other green algae, Platymonas and Pleurastrum.
MICROFLUOROMETRIC MEASUREMENT OF DNA IN EUDORINA ELEGANS AND E. CALIFORNICA (CHOROPHYCEAE)1
Authors: Lindley Kemp C. , Doyle Gordon , Anderson Ron
Published: August 2007

The fluorescent dye 2,5‐bis (4′‐aminophenyl (1′))‐1,3,4‐oxidiwle (BAO) was compared to the Feulgen procedure as a method for quantitative comparison of DNA levels in two species of Eudorina. The BAO procedure proved to be specific and as quantitative as the Feulgen procedure, and was more convenient and rapid. The DNA level of the nuclei of gonidial cells of Eudorina elegans Ehrenberg and E. californica (Shaw) Goldstein doubled prior to each division. The DNA level of the somatic, usually non‐dividing nuclei of E. californica did not vary from the IC (haploid) level.
NORTH CAROLINA MARINE ALGAE. IX. ONSLOWIA ENDOPHYTICA GEN. ET SP. NOV. (PHAEOPHYTA, SPHACELARIALES) AND NOTES ON OTHER NEW RECORDS FOR NORTH CAROLINA1
Authors: Searles Richard B. , Leister Geoffrey L.
Published: August 2007

Four benthic algae are reported here for the first time in the North Carolina flora. The new brown algal genus and species, Onslowia endophytica Searles, is described as an endophyte of Halymenia floridana from the North Carolina continental shelf. New records of Boodleopsis pusilla and Naccaria corymbosa from North Carolina constitute range extensions of these tropical species on the American coast north from Florida. Blastophysa rhizopus, an endophyte and epiphyte known from the North Atlantic coast of Europe and America as well as the Caribbean is reported from North Carolina for the first time and in a new host, Predaea feldmannii.
HOT WATER EXTRACTABLE PHOSPHORUS—AN INDICATOR OF NUTRITIONAL STATUS OF PERIDINIUM CINCTUM (DINOPHYCEAE) FROM LAKE KINNERET (ISRAEL)?1
Authors: Wynne David , Berman Thomas
Published: August 2007

The intracellular levels of hot water extractable and total phosphorus were determined in the dinoflagellate Peridinium cinctum. f. westii (Lemm.) Lef. for natural samples from the bloom in Lake Kinneret and from laboratory cultures. Amounts of phosphorus (P) in the hot water fraction, relative to total cellular phosphorus, were similar in lake Peridinium and in cells grown in high ambient orthophosphate (Pi) media (3–6 mg P · l−1). The absolute amounts of hot water extractable P in natural cell and those cultured at lower Pi concentrations (0.02–0.05 mg P · 1−1) were similar, although average Pi in lake water were 4 μg · l−1. Under most growth conditions the hot water extract contained approximately equal amounts of molybdate reactive phosphorus (MRP) and non‐MRP. Short chain (6–9 units) polyphosphates (mol wt 630–950) probably constituted the bulk of the non‐MRP pool, which was hydrolysable by alkaline phosphatase and may serve as a precursor for a more permanent P store. Intracellular P levels and distribution were not directly dependent on external Pi concentrations but may be determined by the N:P atomic ratio or overall external ionic milieu. Peridinium grown in low ambient Pi released significant amounts of non‐MRP compounds. In Lake Kinneret, for at least most of the bloom period, Peridinium does not appear to be limited by P supply.
COMPARISON OF IN SITU PHOTOSYNTHETIC ACTIVITY OF EPIPHYTIC, EPIPELIC AND PLANKTONIC ALGAL COMMUNITIES IN AN OLIGOTROPHIC LAKE, SOUTHERN FINLAND1
Authors: Kairesalo Timo
Published: August 2007

The photosynthetic activity of different algal communities at the outer edge of an Equisetum fluviatile L. stand in an oligotrophic lake (Pääjärvi, in southern Finland) was investigated. Production by the algal communities was measured simultaneously using a modified 14C‐method, and the results were related to the volume of algae and the available irradiance. The relative production rate (P/B quotient) of phytoplankton was ca. 3 × that of epiphyton and ca. 20 × that of epipelon. Epiphyton productivity remained almost constant although the algal volume varied greatly, suggesting that the surface layer of the algal community was mainly responsible for the photosynthetic activity. In the littoral area (at 1 m depth) primary production/m2 of lake surface by phytoplankton, epiphyton and epipelon was similar but in the littoriprofundal area (2–4 m) phytoplankton production was twice that of epipelon. Primary productivity of epiphyton and epipelon/m2 of substratum was about equal to phytoplankton productivity/m3 of water at the same irradiance. This relation provided a means of estimating the relative contributions of the different algal communities to the total algal production in the lake.
PRESENCE OF A SULFATED POLYSACCHARIDE IN THE EXTRACELLULAR MATRIX OFPLATYDORINA CAUDATA(VOLVOCALES, CHLOROPHYTA)1
Authors: Crayton M. A.
Published: August 2007

Evidence for the presence of a sulfated polysaccharide component within the extracellular matrix ofPlatydorina caudataKofoid is presented. In situ staining with alcian blue and toluidine blue O indicates accumulation of a sulfated polysaccharide in the matrix. The entire matrix was readily solubilized by a hot aqueous extraction and a sulfated proteoglycan complex was isolated. Thin‐layer chromatography of hydrolysates and infrared analysis and chemical desulfation of the intact molecule indicate that the polysaccharide component is principally an arabinogalactan with ester‐linked sulfate groups. Protease treatment of the extract revealed two distinct bands separable on cellulose acetate electrophoresis. The slower moving component was a sulfated glycoprotein while the faster moving component was a sulfated mucopolysaccharide essentially free of protein. This is the first report of specific chemical analyses and electrophoretic separation of a sulfated polysaccharide within the matrix of a member of the Volvocales. The cytochemistry and electrophoretic patterns of theP. caudatapreparation are compared with the same type of extract made fromChlamydomonas reinhardtiiDang. The possible evolutionary significance of the electrophoretic patterns is presented.
VALVE AND BAND MORPHOLOGY OF SOME FRESHWATER DIATOMS. II. INTEGRATION OF VALVES AND BANDS IN NAVICULA CONFERVACEA VAR. CONFERVACEA12
Authors: Rosowski James R.
Published: August 2007

Chemically cleaned and critical‐point dried cells of a clonal culture were examined with scanning electron microscopy. Cells form filaments by valve‐to‐valve connections maintained by organic material which adheres to the central area of the valve face. Bending of filaments is probably restricted to some extent by the articulation of overlapping spatulate marginal spines with an adjacent underlapping set of much shorter spines (ridges), and with the mantle edge itself. Cell division results in three possible spine patterns for each cell: a set of overlapping and a set of underlapping spines; no overlapping sets of spines (two underlapping); or two sets of overlapping spines (no underlapping). Each filament inherits cells with spine set patterns in the ratio of 2 (with 1 set overlapping): 1 (with no sets overlapping): 1 (with 2 sets overlapping). Valvocopulae are shaped similarly to pleurae except that the partes exteriores of the valvocopulae are wider. The pars interior of both is delimited by an advalvar row of pores continuous around the cell apex. The pars exterior also has a row of pores, but it is median in the valvocopula and first pleura and does not continue around the cell apex. The valvocopulae always underlap the mantle and the pleurae always underlap their preceding band. The ends of both appeared attached, but may become free in acid‐cleaned preparations. Bands alternate with each other so that the ends of the valvocopula attach to the first continuous apical portion of the first pleura; the ends of the first pleura attach in that same fashion to the second pleura but at the opposite apex; and all subsequent pleurae alternate in the same fashion with up to at least 13 pleurae/epicingulum. The continuous apical portion of each band is elevated so that a functional (but not structural) ligula is formed, with the continuous apical portion of alternate bands becoming adjacent and underlapping each other only in this region. The valvocopulae in a single cell, or of adjacent cells, may have their continuous apical ends on the same or on opposite apices. It is recommended that N. confervacea var. peregrina (W. Sm.) Grun. be merged with the nominate variety.
CHLOROPELTA GEN. NOV., AN ULVACEOUS GREEN ALGA WITH A DIFFERENT TYPE.OF DEVELOPMENT1
Authors: Tanner Christopher E.
Published: August 2007

A diminutive, distromatic ulvaceous green alga was collected in southern California and studied in culture. The initial stages of development resemble those found in the Ulvaceae sensu Bliding. Germlings pass through a uniseriate filamentous stage, a multiseriate stage and a monostromatic saccate stage. At this stage the development departs from the developmental patterns found in the Ulvaceae. Each cell of the monostromatic upright portion of the germling undergoes a single division in a plane parallel to the surface of the germling to form a distromatic saccate germling. Rupture of the apical end of the germling and continued growth eventually results in a peltate distromatic alga superficially resembling Ulva. Based on the developmental pattern, which is unique to the green algae, the new genus Chloropelta gen. nov. and new species Chloropelta caespitosa sp. nov. are proposed for this alga.
PHYTOCHROME‐MEDIATED STIPE ELONGATION IN THE KELP NEREOCYSTIS (PHAEOPHYCEAE)1
Authors: Duncan Mary Jo , Foreman Ronald E.
Published: August 2007

Preliminary evidence is presented which indicates that far‐red irradiation promotes and near‐red inhibits rapid stipe elongation in Nereocystis luetkeana (Mertens) Postels & Ruprecht. Laboratory results showed afar‐red reversal of red inhibition, but a red/far‐red reversal was not evident in field experiments. The effects of changing ratios of red and far‐red irradiation brought about by selective water absorption are discussed in relation to stipe elongation of Nereocystis.
PROPOSED NEW IDENTIFICATION CHARACTER FOR THE GENUSCOLACIUM(EUGLENOPHYCEAE)1
Authors: Willey Ruth L.
Published: August 2007

Cells of the genusColaciumEhrenberg can be distinguished with the light microscope from cells of the genusEuglenaEhrenberg by the presence of basophilic granules in the anterior tip of theColaciumcell which are clustered around the canal opening. The granules exhibit a biphasic pattern of osmiophilia in electron micrographs. Together with the occasionally obscure character of the paramyloncapped, inner pyrenoids, the granules should serve as a useful character to distinguish between the motile, flagellated cells of the two genera whether from laboratory cultures or from field collections of natural populations.
OLISTHODISCUS LUTEUS (CHRYSOPHYCEAE). V. ITS OCCURRENCE, ABUNDANCE AND DYNAMICS IN NARRAGANSETT BAY, RHODE ISLAND1
Authors: Tomas Carmelo R.
Published: August 2007

The distribution and abundance of the flagellate Olisthodiscus luteus Carter were examined over a 17 yr period (1959–75) at one station in lower Narragansett Bay, Rhode Island, and at many stations throughout the Bay during the 1974, 1975 summer bloom periods. A bimodal pattern of maximum abundance characterized the 17 yr data set. Maxima (103–104 cells·ml−1) occurred during June–July and October–November separated by a mid summer (August) minimum of <102 cells·ml−1. This species was also absent from surface waters during the winter months (January–February) of each year. Regional abundances reached maximal densities of >105 cells·ml−1 during June 1974 and were confined to the northern and western regions of Narragansett Bay. Incident light, temperature, salinity and nutrient (NH4+, NO3−, NO2−, PO43‐) levels were also determined. The abundance cycle appears to be strongly effected by temperature, life cycle, motility, excreted substances and, to lesser extent, by light intensity, salinity, and nutrient dynamics. Regional distribution is affected by motility, wind forced water movements and benthic stage formation. The autecological data for O. luteus, pertinent observations of herbivorous zooplankton and the field observations are used to assess causative factors regulating the dynamics of O. luteus populations in Narragansett Bay. Pratt's hypothesis on the interaction between this species and Skeletonema costatum (Grev.) Cleve is reexamined.
MICROSPECTROPHOTOMETRIC ANALYSIS OF MITOSIS AND DNA SNYTHESIS ASSOCIATED WITH COLONY FORMATION IN PEDIASTRUM BORYANUM (CHLOROPHYCEAE)1
Authors: Millington William F. , Rasch Ellen M.
Published: August 2007

Patterns of DNA synthesis and mitosis in the coenobial alga Pediastrum boryanum (Turp.) Meneghini were analyzed by cytophotometric measurements of individual, Feulgen‐stained nuclei from swarming zoospores aggregating into colonies, and cells in colonies varying in age from 12 to 96 h after their initial transfer to fresh culture medium. A haploid genome size of 0.2 pg DNA (corresponding to roughly 11 × 1012 daltons, or 1.64 × 105 kb) was estimated by comparative measurements of nuclei from zoospores or young colonies and chicken erythrocyte (RBC) nuclei which were included with each set of Pediastrum slides as an internal reference standard of 2.5 pg DNA/cell. Although nuclear morphology and extent of chromatin condensation vary with different stages of colony development, nuclear division in P. boryanum appears to follow each cycle of DNA replication with no accumulation of DNA beyond the 2C level. Cytoplasmic cleavage resulting in the formation of individual zoospores is delayed until completion of mitosis, as is the demise of the pyrenoid. After 96 h of culture, 40% of all colonies have cells that are 8‐ or 16‐nucleate and some colonies have 32 nuclei/cell. Release of zoospores within vesicles occurs at this time to complete a cycle of asexual reproduction.
HOST‐RANGE, PLAQUE‐MORPHOLOGY STUDIES OF CYANOPHAGE LPP‐11
Authors: Kraus Marjorie P.
Published: August 2007

Transduction by temperate cyanophage plays an important role in understanding the effects of environmental pollution on genetic function. Using a new isolate, this paper illustrates the influence of contaminants and the rapid variations that result as a virus particle passes through successive hosts. Host‐range and plaque‐morphology, using an extended range of genetically‐differing hosts, compares archetype LPP‐1 cyanophage cultured on microbially contaminated hosts with bacteria‐free cyanophage cultured on pure host strains. Microbial contamination can alter the host‐range and serology of the cyanophage produced. It is suggested that bacteria are involved in the virus infection of cyanophycean hosts and that the study of host‐range and plaque‐morphology can aid in the biological characterization and segregation of mutants illustrating mechanisms of inter generic transfer of genetic material. It is shown that derivatives of archetype LPP‐1, cultured on axenic hosts, possess a host‐range, plaque‐morphology and serology similar or identical to that of the temperate cyanophage, S3.
ULTRASTRUCTURE CHARACTERISTICS OF MONOSPORE FORMATION IN PORPHYRA GARDNERI (RHODOPHYTA)1
Authors: Hawkes Michael W.
Published: August 2007

Monosporogenesis in Porphyra gardneri (Smith & Hollenberg) Hawkes has been examined with the transmission electron microscope. Increased dictyosome activity resulting in the production of small and large fibrous vesicles is a characteristic feature of the developing monospores. Released monospores lack a cell wall. Four of the six Porphyra species commercially cultivated in Japan form monospores. Monospore production is of economic importance because it results in an increased number of foliose thalli.
BACTERIA INDUCED POLYMORPHISM IN AN AXENIC LABORATORY STRAIN OF ULVA LACTUCA (CHLOROPHYCEAE)1
Authors: Provasoli Luigi , Pintner Irma J.
Published: August 2007

A laboratory culture of Ulva lactuca L. purified with antibiotics in 1958 can assume different morphologies. In synthetic media of the ASP type it grows as a pin‐cushion composed of uniseriate branching filaments. Only occasionally some finger‐like germlings appear which, after a few millimeters growth, disintegrate and originate the branched uniseriate filaments. Many strains of marine bacteria, isolated from Ulva and other seaweeds collected in nature or from laboratory cultures, when grown together with this axenic Ulva, induced growth of long thin Enteromorpha‐like tubes (active bacteria). Other bacterial strains have no visible morphological effect on the Ulva (inactive). Combinations of several active and inactive bacterial strains result in flat ribbons which can be wide or narrow and with distromatic portions intercalated between tubular portions. No combination has so far induced the axenic Ulva to produce the typical expanded foliose thallus. Bacterial filtrates are inactive; syntrophic growth seems indispensable. The bacterial strains lose the ability to induce morphogenic effects on the axenic Ulva when grown for several transfers in organic marine media and regain it by growing with Ulva for several transfers in synthetic mineral media. Each partner appears therefore to be dependent on the metabolites produced by the other. The perpetuation of a wide morphological versatility of this laboratory strain of Ulva after 15 yr maintenance under under artificial conditions emphasizes the phylogenetic importance of this versatility.
SPHACELARIA LACUSTRIS SP. NOV., A FRESHWATER BROWN ALGA FROM LAKE MICHIGAN1
Authors: Schloesser Robert E. , Blum John L.
Published: August 2007

The growth, reproduction and ultrastructure of a new freshwater phaeophyte, Sphacelaria lacustris sp. nov., are described. The plant occurs as a minute calcified thallus at 5–15 m depth along the western shoreline of Lake Michigan. Both freshly collected and laboratory grown plants show apical growth of erect and basal filaments, intermittent longitudinal divisions in filament segments, vegetative reproduction by propagules, numerous parietal chloroplasts and an absence of pyrenoids, characteristics of Sphacelaria. This material is separated from the only other freshwater species in the genus (S. fluviatilis Jao) at least by differences in longitudinal septation, in branching, in its propagules and in general aspect. Between this plant and marine brown algae there are essential similarities of ultrastructure of cell wall and pores, chloroplasts, mitochondria, nucleus and the production/excretion of physodes.
HISTORICAL BIOGEOGRAPHY OF CHARA (CHAROPHYTA): AN APPRAISAL OF THE BRAUN‐WOOD CLASSIFICATION PLUS A FALSIFIABLE ALTERNATIVE FOR FUTURE CONSIDERATION1
Authors: Proctor Vernon W.
Published: August 2007

To that classification of the genus Chara, first advanced by Braun in 1847 with subsequent reiteration by the same author in 1867 and 1882 and by Wood in 1962 and 1965, an alternative is here proposed. Contended strengths of the present model include: i) a more accurate reflection of the phylogeny of the genus; ii) conformity with current distribution of dioecious taxa assumed consistently ancestral to their monoecious, morphological counterparts; iii) assumption of allopatric speciation primarily as a result of tectonic movement; and, iv) a foundation of underlying conjecture nearly all of which is potentially falsifiable in the Popperian sense as well as predictive with respect to a wide array of features. Deemphasized or rejected are previous assumptions that; i) stipulode, and to a lesser extent cortical, development reflect major evolutionary trends; ii) endemism is rare in the Charophyta; iii) dioecism and monoecism can be accommodated infraspecifically; iv) evolutionarily significant transitions between the preceding occur in both directions; v) hybridization contributed significantly to the phylogeny of the Charophyta; vi) section Grovesia is monophyletic in origin; and, vii) the Chara flora of Australasia arrived via India. The evidence upon which this classification rests is considered primarily with respect to the genus Chara, although the model appears equally applicable to the genus Nitella.
PARAMYLON SYNTHESIS IN HETEROTROPHIC AND PHOTOHETEROTROPHIC EUGLENA (EUGLENOPHYCEAE)1
Authors: Briand Joël , Calvayrac Régis
Published: August 2007

Growth of Euglena gracilis Klebs in medium containing DL‐lactate as sole carbon source results in the synthesis of large quantities of paramylon at the beginning of exponential growth. The accumulation of paramylon grains in the cytoplasm is observable in both dark‐grown and light‐grown cells. Furthermore, the cells fix 14CO2 in darkness. Incorporated CO2 is found in paramylon which is function of the physiological state of the cells, being most intense in exponential phase heterotrophic Euglena. The mitochondria undergo structural modifications in older cultures, i.e., when the exogenous carbon source becomes exhausted. At the beginning of exponential growth, they are swollen and vesiculated with an electrontranslucent matrix containing an extensive internal membrane system. This vesiculated mitochondrial system is correlated with paramylon synthesis, since forming paramylon grains are seen within the vesiculated complex. Stationary phase cells present a compact chondriome with a dense matrix devoid of vesiculation. Membrane‐bound paramylon grains are found in the cytoplasm of these cells.
EFFECT OF GROWTH SUBSTANCES ON “APICAL DOMINANCE” IN SPHACELARIA FURCIGERA (PHAEOPHYTA)1
Authors: Dworetzky Beth , Klein Richard M. , Cook Philip W.
Published: August 2007

Gibberellic acid (GA), naphthaleneacetic acid (NAA), and kinetin (K) were tested individually and in combinations on the development of filaments of Sphacelaria furcigera Kütz. Unbranched tips from filaments with or without intact apical cells were grown in the presence or absence of growth substances to study their effects on an apical‐dominance‐like response previously observed in this genus. Removal of the apical cell resulted in lateral branches developing significantly closer to the tip than in uninjured controls. GA and K had no effect on location of lateral branches of uninjured filaments, but exerted some control as evidenced by increases in the distance from a punctured apical cell to the nearest lateral branch. NAA had no positive effects and was toxic in even moderate concentrations. The three growth substances in all combinations could not fully replace the apical cell in repressing branch development. GA and K presented simultaneously were no more effective than either presented alone.