bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARATIVE MORPHOLOGY, CROSSABILITY, AND TAXONOMY WITHIN THE CALOGLOSSA CONTINUA (DELESSERIACEAE, RHODOPHYTA) COMPLEX FROM THE WESTERN PACIFIC
Authors: Kamiya Mitsunobu , Tanaka Jiro , Hara Yoshiaki
Published: October 2004

Systematic studies were undertaken on the Caloglossa continua (Okamura) King et Puttock complex from Japan, Singapore, and Australia, based on morphology and reproductive compatibility. Specimens from Japan had two to six cell rows derived from a nodal axial cell, at the margin opposite the branch, whereas those from Australia possessed only a single cell row. Specimens from Singapore formed one to four cell rows per nodal axial cell and always contained at least one single cell row on any one thallus. These differences were maintained in cultured materials over a range of temperatures or salinities. Type material of C. continua had the same morphology as the Japanese specimens in this study. Carpospores discharged from the Japanese isolate germinated at 10°C, whereas those from Singapore and Australia died at this temperature. In hybridization experiments, the Japanese entity was completely nonfertile with both the Singaporean and Australian isolates. Many pseudocystocarps were produced in the crossing between the male from Australia and the female from Singapore, although the reciprocal combination did not produce any such structures. On the basis of the discontinuous morphology coupled with the complete reproductive isolation, the entities from Singapore and Australia are described here as C. monosticha sp. nov. The entities with multiple cell rows likely expanded their geographic range from tropical regions, where the majority of Caloglossa species are now distributed, to high‐latitude regions, and such an expansion would be associated with acquiring low‐temperature tolerance.
THE CYST‐THECA RELATIONSHIP IN CALCIODINELLUM OPEROSUM EMEND. (PERIDINIALES, DINOPHYCEAE) AND A NEW APPROACH FOR THE STUDY OF CALCAREOUS CYSTS
Authors: Montresor Marina , Janofske Dorothea , Wallems Helmut
Published: October 2004

The paratabulate calcareous cyst of Calciodinellum operosum Deflandre was recorded in a sediment trap sample collected in the Bay of Naples (Tyrrhenian Sea, Italy). The germination of this resting stage produced a phototrophic vegetative cell that had the typical plate pattern of a Scrippsiella species. The cyst morphotypes, observed in a clonal culture of this species, ranged from cysts with well‐developed paratabulation to cysts in which the paratabulation was barely visible, to cysts covered by irregularly shaped crystals. The analysis of thin sections of the calcareous cysts using the polarized light microscope equipped with crossed nicols and a gypsum plate showed that the optical orientation of the calcite crystals was tangential in all the morphotypes examined. We suggest that the crystallographic method we describe might provide insights for calcareous cyst taxonomy and phylogeny.
PHYLOGENETIC AFFINITIES OF CRYSONEPHELE PALUSTRIS (CHRYSOPHYCEAE) BASED ON INFERRED NUCLEAR SMALL‐SUBUNIT RIBOSOMAL RNA SEQUENCE
Authors: Saunders Gary W. , A. Hill David R. , Tyler Peter A.
Published: October 2004

The nuclear small‐subunit ribosomal DNA sequence was determined from the colonial chromophytic alga Chrysonephele palustris Pipes, Tyler, et Leedale using polymerase chain reaction methods. The inferred ribosomal RNA sequence was included in a multiple alignment, containing heterokont chromophytes, and subjected to molecular systematic analyses in order to determine the phylogenetic relationships of this alga. Chrysonephele palustris grouped within the Chrysophyceae and not in an intermediate position between the Chrysophyceae and Eustigmatophyceae, suggesting that Chrysonephele is not a phylogenetic link between these algal classes.
A PHYLOGENETIC ANALYSIS OF THE SYNUROPHYCEAE USING MOLECULAR DATA AND SCALE CASE MORPHOLOGY
Authors: Lavau Stephanie , Saunders Gary W. , Wetherbee Richard
Published: October 2004

The phylogeny of the Synurophyceae was investigated by parsimony analysis of scale case characters and small‐sub unit (18S) ribosomal RNA (rRNA) sequence data. Analysis of 1 eustigmatophycean (outgroup), 3 chrysophycean, and 10 synurophycean 18S rRNA sequences corroborated the inference from ultrastructural information that the Synurophyceae is a monophyletic assemblage. Tessellaria vol‐vocina, which had been tentatively proposed as a member of the Synurophyceae, was confirmed as the earliest lineage within the Synurophyceae by both the molecular analysis and an evaluation of published ultrastructural data. A second set of analyses investigated the relationships among Tessellaria volvocina, 6 Synura species, and 10 Mallomonas species/varieties, with particular reference to the validity of current classifications of the Synurophyceae and the characters upon which they are based. The molecular and scale case phylogenies were not totally resolved but were largely congruent. The data sets were combined to produce another phylogeny, which showed greater resolution. The combined phylogeny weakly supported our representatives of Synura and Mallomonas as monophyletic groupings and also upheld several of the sections within these genera that are recognized by current classifications. However, some changes to the classification and delineation of these genera are recommended and predicted. Both our 18S rRNA sequence and scale case data sets were more appropriate for examining the branching order among the more closely related text rather than resolving the deeper branching points of the synurophycean phylogeny.
MOLECULAR SYSTEMATICS OF ECTOCARPUS AND KUCKUCKIA (ECTOCARPALES, PHAEOPHYCEAE) INFERRED FROM PHYLOGENETIC ANALYSIS OF NUCLEAR‐ AND PIASTTD‐ENCODED DNA SEQUENCES
Authors: Stache‐Crain Birgit , Müller Dieter G. , Goff Lynda J.
Published: October 2004

The phylogeny of Ectocarpus and Kuckuckia strains representing widely separated populations from both hemispheres was inferred from sequence analysis of the internal transcribed spacers of the nuclear ribosomal DNA (ITS 1—5.8S‐ITS 2) and the spacer region in the plastid‐encoded ribulose‐bis‐phosphate‐carboxylase (RUBISCO) cistron (partial rbc L‐spacer‐partial rbc S). Both sequences resulted in matching phylogenies, with the RUBISCO spacer region being most informative at the level of genera and species and the internal transcribed spacer sequences at the level of species and populations. Three major clades were formed by strains previously described by morphology and physiology as Kuckuckia, E. fasciculatus, and E. siliculosus, confirming the validity of these taxa. Ectocarpus and Kuckuckia are regarded as sibling taxa with respect to the outgroup species Feldmannia simplex, Hincksia mitchelliae, and Pilayella littoralis. The clade formed by sexual E. siliculosus strains and most asexual Ectocarpus strains was subdivided into several clades that are consistent with geographical races within E. siliculosus. The inferred phylogeny of Ectocarpus corresponds generally with results from cross‐fertilization experiments, morphology, and lipid analysis. A hypothesis on the origin and dispersal of E. siliculosus suggests several natural dispersal events during periods of global cooling as well as recent and possibly anthropogenic dispersal events.
ELEMENTAL COMPOSITION, CORRELATIONS, AND RATIOS WITHIN A POPULATION OF STAURASTRUM PLANCTONICUM (ZYGNEMATALES): AN X‐RAY MICROANALYTICAL STUDY1
Authors: Sagee David C. , Holland Ruth
Published: October 2004

Individual cells of Staurastrum planctonicum (Teil.) within a mixed freshwater phytoplankton sample were analyzed by scanning electron microscope X‐ray microanalysis to determine their elemental composition. X‐ray emission spectra routinely showed clear peaks of P, S, and Cl, plus monovalent (Na, K, and divalent (Mg, Ca) cations. Si and Cu were also present in lower quantities. Concentrations of individual elements (expressed as mmol.kg−1 dry weight) varied widely among cells, with values over the sample population approximating to a normal distribution. Although intracellular anion and cation levels varied considerably, significant correlations occurred between concentrations of monovalent and divalent cations (mean ratio 1.4), major diffusible anions and cations (mean ratio 1,2), and total levels of electropositive and electronegative elements (mean ratio 1.2). The monovalent cations of K and Na occurred at a mean ratio of 1.2 and were not significantly correlated.

Concentrations of individual elements (except Si) showed clear positive correlations within the analyses, with 12 highly significant (99% probability) correlations out of 36 possible combinations. Principal factor analysis showed that elemental correlations were determined by two major factors, with two resulting groups of elements—(Na, S, Cl, Ca, Cu) and (Mg, P, K). Statistical relationships between elements followed a clear correlation pattern, which retained its characteristics even when elemental concentrations were expressed per unit P rather than per unit dry weight. Elemental concentrations were closely similar in matching, but not nonmatching, smicells.

The statistical pattern of elemental associations noted in Staurastrum parallels that seen in X‐ray micro‐analytical studies of other algae but differs in detail. This pattern of statistical associations has biological implications in terms of cell compartmentation, characterization of different cell types, and cell interactions with their environment.
RECENT APPEARANCE OF CYLINDROSPEMOPSIS (CYANOBACTEIUA) IN FIVE HYPEREUTROPHIC FLORIDA LAKES1
Authors: Chapman Andrew D. , Schelske Claire L.
Published: October 2004

Observations of historical and recent phytoplankton samples from five hypereutrophic Florida lakes indicate that nitrogen‐fixing cyanobacteria in the genus Cylindrospermopsis Seenayya et Subba Raju have entered these water‐bodies sometime in the last 30 years. Cylindrospermopsis forms a year‐round bloom in one of the five lakes, dominates seasonally in another, and is at least at times an important component of the phytoplankton community in the remaining three. The increase in abundance of Cylindrospermopsis in Florida lakes could have implications for water management.
DIVERSITY OF HALOGENATED SECONDARY METABOLITES IN THE RED ALGA LAURENCIA NIPPONICA (RHODOMELACEAE, CERAMIALES)1,2
Authors: Masuda Michio , Abe Tsuyoshi , Sato Shinji , Suzuki Teruaki , Suzuki Minoru
Published: October 2004

Many morphologically similar, but chemically distinct, populations have been found in the marine red alga Laurencia nipponica Yamada (Rhodomelaceae, Ceramiales) growing in Japan. Each chemical type is characterized by a specific end‐product of halogenated secondaly metabolite synthesis: chamigrane‐type sesquiterpenoids such as prepacifenol and halochamigrene epoxide and C15 bromoethers such as laurencin, laureatin, isoprelaurefucin, epilaurallene, and kumausallene. These seven types of secondary metabolite syntheses remained the same in the wild and under various culture conditions. Because bromoethers and terpenoids are probably synthesized by different metabolic pathways, it is virtually certain that different sets of enzymes participate in their synthesis. Prepacifenol‐ and laureatin‐producing populations were selected as representatives of terpenoid and bromoether groups, respectively. F1 tetrasporophytes derived from crosses between reciprocal, female and male gametophytes of prepacifenol‐ and laureatin‐producing strains bore both types of metabolites, suggesting that the genes Producing these enzyme systems are encoded by nuclear genomes. The F1 gametophytes resulting from the reciprocal crosses produced either prepacifenol or laureatin, and the four individuals derived from spore tetrads (a set of tetraspores derived from a single tetrasporangium) produced either prepacifenol or laureatin in a 1:1 ratio, indicating that genes participating in terpenoid synthsis and those participating in bromoether synthesis are on different loci of homologous chromosomes and are segregated at meiosis (tetrasporogenesis). One individual of this interpopulational F1 gamtophyte produced both parental types of metabolite, perhaps indicating the occurrence of a recombination type. Natural hybrid individuals, including such recombination‐type gametophytes, were found in a sympatric locality at which these two chemical types occur. F1 tetrasporophytes derived from crosses between respective prepacifenol‐ and laureatin‐producing strains and their F1 gametohytes produced only parental‐type metabolite‐producing plants. These results indicate that the diverse chemical types can be referred to as races (chemical races).
DIURNAL FLUCTUATION OF NITRATE REDUCTASE ACTIVITY IN THE MARINE RED ALGA GRACILARIA TENUISTIPITATA (RHODOPHYTA)1
Authors: Lopes Patrícia F. , Oliveira Mariana C. , Colepicolo Pio
Published: October 2004

The biochemical characteristics and diurnal changes in activity of the enzyme nitrate reductase (NR; EC 1.6.6.1) from the marine red alga Gracilaria tenuistipitata var. liui Zhang et Xia are described. Different assay conditions were tested to determine the stability of NR. The crude extract of G. tenuistipitata has a NR specific activity of 10.2 U.mg−1, which is higher than the NR activities found for other algae, plants, and fungi. This NR is highly active at a slightly alkaline pH and is stable over a wide range of temperature, with an optimal activity at 20° C. The apical portions of the thallus contain 64.9 ± 6.6% of the total NR specific activity. The apparent Michaelis‐Menten (Km) constant found for KNO3 was 197 μM, and it was 95 μM for NADH. The NR from G. tenuistipitata can be included in the NADH‐specific group, because no activity was found when NADPH was used as an electron donor. In extracts of algae grown under either continuously dim light or a light‐dark cycle, the activity of NR exhibits a daily rhythm, peaking at the middle of the light phase, when activity is 30‐fold higher than during the night phase.
THE CYTOSKELETON OF THE NAKED GREEN FLAGELLATE SPERMATOZOPSIS SIMILIS (CHLOROPHYTA):FLAGELLAR AND BASAL BODY DEVELOPMENTAL CYCLE1
Authors: Lechtreck Karl‐Ferdinand , Reize Ingo Botho , Melkonian Michael
Published: October 2004

Flagellar and basal body development during cell division was studied in the biflagellate green alga Spermatozopsis similis Preisig et Melkonian by light microscopy of immobilized living cells, statistical analysis of flagellar lengths during the cell cycle, and electron microscopy of cells and isolated cytoskeletons. Interphase cells display two flagella of unequal/subequal length. An eyespot located in an anterior lobe of the chloroplast is connected to the basal body bearing the shorter flagellum by means of a five‐stranded microtubular root. Until cell division, the two parental flagella attain the same length. During cell division, each cell forms two new flagella that grow to a length of 1.5 μm before they are distributed in a semiconservative fashion together with the parental flagella to the two progeny cells at cytokinesis. During the following interphase, the flagella newly formed during the preceding cell division grow to attain the same length as the parental flagella until the subsequent cell division. The shorter of the two flagella of a cell thus represents the developmentally younger flagellum, which transforms to the mature state during two consecutive cell cycles. Interphase cells display only two flagella‐bearing basal bodies; two nascent basal bodies are formed during cell division and are connected to the microtubular d‐roots of respective parental basal bodies with which the newly formed basal bodies are later distributed to the progeny cells. During segregation, basal body pairs shaft into the 11/5 o'clock direction, thus conserving the 1/7 o'clock configuration of basal body pairs of interphase cells. Prior to chloroplast and cell division, an eyespot is newly formed near the cell posterior in close association with a 1s microtubular root, while the parental eyespot is retained. During basal body segregation, eyespot‐root connections for both the old and newly formed eyespots are presumably lost, and new associations of the eyespots with the 2s roots of the newly formed basal bodies are established during cytokinesis. The significance of this “eyespot‐flagellar root developmental cycle” for the absolute orientation of the progeny cells is discussed.
PHYLOGENYOF CHLOROMONAS (CHLOROPHYCEAE): A STUDY OF 185 RIBOSOMAL RNA GENE SEQUENCES1
Authors: Buchheim Mark A. , Buchheim Julie A. , Chapman Russell L.
Published: October 2004

The unicellular, biflagellate genus Chloromonas differs from its ally, Chlamydomonas, primarily by the absence of pyrenoids in the vegetative stage of the former. As with most green flagellate genera, little is known about phylogenetic affinities within and among Chloromonas species. Phylogenetic analyses of nuclear‐encoded small‐subunit ribosomal RNA gene sequences demonstrate that a sampling of five Chloromonas taxa, obtained from major culture collections, do not form a monophyletic group. However, only three of these isolates, Chloromonas clathrata, Chloromonas serbinowi, and Chloromonas rosae, are diagnosable morphologically as Chloromonas species by the absence of a pyrenoid in the vegetative stage. The three diagnosable Chloromonas taxa form an alliance with two pyrenoid‐bearing chlamydomonads, Chlamydomonas augustae and Chlamydomonas macrostellata. With the exception of Chloromonas serbinowi, which represents the basal lineage within the clade, each of the diagnosable Chloromonas taxa and their pyrenoidbearing Chlamydomonas allies were isolated originally from mountain soils, snow, or cold peat. These observations suggest that habitat, independent of pyrenoid status, may be most closely linked to the natural history of this clade of chlamydomonad flagellates.
INFECTIOUS DISEASES OF MAZZAELLA LAMINARIOIDES (RHODOPHYTA): CHANGES IN INFECTION PREVALENCE AND DISEASE EXPRESSION ASSOCIATED WITH SEASON, LOCALITY, AND WITHIN‐SITE LOCATION1
Authors: Corren Juan A. , Buschmann Alejandro , Retamales Claudia , Beltrán Jessica
Published: October 2004

This study addresses the issues of infection prevalence and disease expression in two wild populations of the red algal host Mazzaella laminarioides and their variability associated with locality, season, and spatial location of the host in the intertidal zone. Our results demonstrated that Endophyton ramosum is the most frequent infective pathogen affecting M. laminarioides in Matanzas and Pucatrihue. This situation prevailed through the year and across the high‐to‐low intertidal gradient. Although there was a general trend for lower levels of infection in late winter and early spring, only in a few, cases was well‐defined seasonality detected. Furthermore, clear seasonal patterns, as displayed by deformative disease in the high intertidal zone of Pucatrihue, were attenuated in the middle and lower intertidal zones. Differences in levels of infection in M. laminarioides between the high intertidal zones of Matanzas and Pucatrihue diminished toward the low intertidal zone. Thus, effects of seasonality and locality on infection prevalence may be influenced, at least in part, by the position of the hosts an the intertidal zone.

Spatial distribution of the diseased individuals also varied along the beach. This pattern was consistent between the two sites and seemed related to wave exposure and the specific pathogen. Comparisons of the size distribution of noninfected fronds with their infected counterparts showed that infections by Endophyton ramosum and Pleurocapsa sp. more frequently affected medium‐and large‐sized fronds. This pattern was consistent temporally and similar in the two localities. Finally, a clear association between maturity and prevalence of infection was detected. This association resulted in most fronds of the noninfected segment of the host population being immature, whereas most mature fronds were infected. In conclusion, infectious diseases affecting the red alga Mazzaella laminarioides are a persistent phenomenon in wild populations of the host, although only a small segment of the infected populations displays the full expression of the disease. In spite of the suggested role of factors such as season, latitude, and spatial location of the host on disease prevalence and expression, additional studies are needed to understand fully the dynamics of infectious diseases in wild populations of algal hosts.
THE EFFECT OF A HORN SNAIL ON ULVA EXPANSA (CHLOROPHYTA): CONSUMER OR FACILITATOR OF GROWTH?1
Authors: Fong Peggy , Desmond Julie S. , Zedler Joy B.
Published: October 2004

To determine whether California horn snails are more likely to be consumers or facilitators of Ulva expansa (Setch) S. & G. growth in estuaries, we conducted manipulative experiments that evaluated algal growth and the movement of N between the water column, algal tissue, and, in the second experiment, sediments. Algae grew poorly in the absence of sediments, drawing on their own sequestered N supplies (3.5% of dry weight reduced to <2%) and N released by snails and by depleting inorganic N in the water column. There was no evidence of consumption when snail densities ranged from 0 to 900.m−2 (0, 3, 6, and 9 per aquarium), as algal growth was similar for all snail densities, and snail lengths did not increase during the 21–d experiment. when sediment was provided, N was depleted in the sediment and enhanced in the algal tissue. As in the first experiment, the water column was depleted of inorganic N and enriched with organic N, mostly in the dissolved form. Because both snails and macroalgae often dominate the shallow waters of southern California's lagoons and estuaries, our evidence that the snails are primarily facilitators of algal growth (via transfer of N from sediments to the water column) suggests that snails may play an important role in both food web and N dynamics.
STUDIES ON TRANSPARENT EXOPOLYMER PARTICLES (TEP) PRODUCED IN THE ROSS SEA (ANTARCTICA) AND BYPHAEOCYSTIS ANTARCTICA(PRYMNESIOPHYCEAE)1
Authors: Hong Ying , Smith Walker O. , White Ann‐Maree
Published: October 2004

The distribution and production of transparent exopolymer particles (TEPs) were studied quantitatively both in cultures ofPhaeocystis antarcticaKarsten (Prymnesiophyceae) and in natural phytoplankton assemblages in the Ross Sea, Antarctica. TEP production in culture was a function of growth rate and photosynthetic activity and was strongly influenced by photon flux density. The concentrations of TEP measured during a bloom, dominated byP. antarctica,were higher than those produced by coastal diatom blooms and were correlated with chlorophyll a (Chl a), being low at Chlalevels below 3 μgL−1but increasing rapidly at greater Chlaconcentrations. Because higher chlorophyll hek are dominated 4 largerP. antarcticacolonies, this relationship suggests that TEP was produced primarily by sloughing and disintegration of the colonial matrix. TEP concentrations (both absolute and relative to Chla)increased as the bloom's biomass increased. Vertical distributions of TEP and Chlashowed TEP: chlorophyll maxima at the bottom of the water column at most stations. Because TEP and floc formation are tightly coupled, we suggest that mucous flocs derived from TEP, rather than intactP. antarcticacolonies, are the dominant component of aggregates and subsequent organic carbon vertical flux.
LIGHT‐HARVESTING COMPLEX AF'OPROTEINS IN CYTOPLASMIC VACUOLES IN CHLAMYDOMONAS REINHARDTII (CHLOROPHYTA)1
Authors: Wolfe Oregory R. , Park Hyoungshin , Sharp William P. , Hoober J. Kenneth
Published: October 2004

Cells of Chlamydomonas reinhardtii Dangeard strain cw15arg7A contain electron‐opaque material, often in the form of large granules, within cytoplasmic vacuoles. Immunoelectron microscopy with antibodies to polypeptide 11, a component of the major light‐harvesting chlorophyll (Chl) a/b‐protein complex (LHCII,) of thylakoid membranes, revealed the presence of LHCII Polypeptides within the chloroplast and in vacuolar material in cells grown in the light. Vacuolar material was also heavily immunodecorated in dark‐grown cells that did not synthesize Chl. Accumulation of LHCII polypeptides was further studied in greening and light‐grown cells of a pale green mutant, deficient in LHCII, that was derived from cu15arg7A by insertional mutagenesis. Light‐grown cells of this mutant strain contained relatively few thylakoid membranes and synthesized LHCII polypeptides at a low rate. However, cytoplasmic vacuoles were immunoreactive. Appearance of mature‐sized LHCII polypeptides in vacuoles suggested that these proteins were partially translocated across the envelope but not retained by the chloroplast without assembly of LHCII.
PARASITIC INTERACTIONS AND VEGETATIVE ULTRASTRUCTURE OF CHOREOAEMA THURETII (CORALLINALES, RHODOPHYTA)1
Authors: Broadwater Sharon T. , LaPointe Elizabeth A.
Published: October 2004

The monotypic coralline red alga, Choreonema thuretii (Bornet) Schmitz (Choreonematoideae), grows endophytically within three geniculate genera of the Corallinoideae. Although the thallus of Choreonema is reduced, lacks differentiated plastids, and is endophytic except for its conceptacles, its status as a parasite has been questioned because cellular connections to the host had not been ob served. Transmission electron microscopy, however, disclosed a previously undescribed type of parasitic interaction in which Choreonema interacts with its host through specialized cells known as lenticular cells. These small, lens‐shaped cells are produced from the single file of host‐penetrating vegetative cells. Pit plug morphology between vegetative and lenticular cells is polarized. Plug caps facing the vegetative cell have normal coralline morphology, while those facing the lenticular cell are composed of three layers. Regions of lenticular cells near host cells protrude toward the host cell; upon encountering the host cell wall, the prolrusion produces numerous finger‐like fimbriate processes that make cellular connections with the host cell. Lenticular cells may extend several protrusions toward a host cell or penetrate more than one host cell; two or more lenticular cells may also penetrate the same host cell. The lack of secondary pit connections, cell fusions, and passage of parasitic nuclei suggest that this parasitic relationship may be evolutionarily older than previously reported cases of parasitism in red algae.
SINGLE‐CELL PIGMENTATION OF PORPHYRA LINEARIS ANALYZED BY FOURIER TRANSFORM MULTI‐PIXEL SPECTROSCOPY AND IMAGE ANALYSIS1
Authors: Katz Shlomit , Dubinsky Zvy , Rothmann Chana , Malik Zvi , Friedlander Michael
Published: October 2004

The novel method of Fourier transform multi‐pixel spectroscopy was used for the nondestructive analysis of and comparison of pigmentation in different regions of live thalli of the red alga Porphyra linearis. Because the thallus in this alga consists of a monolayer of nonoverlapping cells, we were able to analyze the pigmentation of single cells by combining light absorbance with natural fluorescence data. From the image of each cell in the vegetative male and female reproductive and holdfast regions, more than 4 ± 104 fluorescence and absorbance spectra were obtained. Specific pigments in the different regions were localized by the use of a software program of similarity mapping followed by image construction. The reconstructed images revealed subcellular localization of each pigment according to specific spectroscopic fingerprints. The results showed that the vegetative and female reproductive cell types had a significantly higher content of phycoerythrin than of phycocyanin, and quite similar chlorophyll a levels. Most of the holdfast cells were poorly pigmented, but had more chlorophyll a than phycoerythrin or phycocyanin. The male reproductive cells contained only traces of pigments. Thus, by using Fourier transform multipixel spectroscopy, we were able to characterize the pigmentation of different regions of the thallus and follow the distribution patterns of the different pigments on the subcellular level along the differentiation gradient of the alga.
DETECTION AND EVALUATION OF A NOVEL SEXUAL PHEROMONE THAT INDUCES SEXUAL CELL DMSION OF CLOSTERIUM EHRENBERGII (CHLOROPHYTA)1
Authors: Fukumoto Ryo‐hei , Fujii Tadashi , Sekimoto Hiroyuki
Published: October 2004

Mating type‐plus (mt+; NIES‐228) cells of Closterium ehrenbergii undergo a division to form gamete‐shaped cells. This cell division is induced by a substance produced by mating type‐minus (mt−; NIES‐229) cells. Light and the presence of mt+ cells enhanced production of the substance. The active substance is heat labile and has an apparent molecular mass of 20 kDa. From these results, we conclude that the substance is a novel, proteinaceous sexual pheromone involved in reproduction of Closterium ehrenbergii.
FIVE NEW GOMPHONEMA SPECIES (BACILLARIOPHYCEAE) FROM RIVERS IN SOUTH AFRICA AND SWAZILAND1
Authors: Passy Sophia I. , Kociolek John P. , Lowe Rex L.
Published: October 2004

Diatom material from South Africa and Swaziland was examined with light and scanning electron microscopy. Five new taxa are proposed: Gomphonema crocodilei, G. quasicrocodilei, G. venusta, G. latistigmata, and G. cholnokyi. Gomphonema venusta has been previously misidentified as Gomphonema clevei Fricke and G. cholnokyi as G. subclavatum (Grunow) Grunow. All of the species possess biseriate striae, areolae with external vela, a true stigma, and marginal laminae underlying the valve margin and mantle. Compared to the other members of gomphonemoid lineage, the five new species show greatest similarity to Gomphoneis mesta Passy‐Tolar & Lowe, G. magna Kociolek & Stoermer, and G. rhombica (Fricke) Merino, García, Hernández‐Mariné, & Fernández and to the Herculeana lineage of Gomphoneis sensu Kociolek and Stoermer. The most recent phylogenetic analysis of the genus Gomphoneis showed that the two lineages of the genus. Herculeana and Elegans, are not monophyletic. The Herculeana lineage is more closely allied to Gomphonema than to the Elegans lineage. Since the Elegans lineage contains the generitype of Gomphoneis (G. elegans (Grunow) Cheve), and the species described here are more closely related to the Herculeana lineage, we have assigned them to Gomphonema.
CHARACTERIZATION OF SCHIZOSERIS CONDENSATA, SCHIZOSERIDEAE TRIB. NOV. (DELESSERIACEAE, RHODOPHYTA)1
Authors: Hommersand Max H. , Fredericq Suzanne
Published: October 2004

The Myriogramme group of Kylin contains two distinct clusters of genera that merit recognition at the tribal level. We previously established the tribe Myriogrammeae, and in this paper we erect the Schizoserideae based on a study of the type species of Schizoseris, S. laciniata (=S. condensata), from the southern hemisphere. The Schizoserideae is characterized by 1) marginal and diffuse intercalary meristems; 2) nuclei initially arranged in a plate in the median plane in meristematic and mature cells; 3) chloroplasts one to few, lobed or dissected; 4) microscopic veins absent; 5) procarps scattered, formed singly on either side of the blade with cover cells absent and consisting of a one‐ to two‐celled lateral sterile group, a one‐ to two‐celled basal sterile group, and a four‐celled carpogonial branch in which the trichogyne passes beneath the lateral sterile group and emerges anterior to it; 6) auxiliary cell diploidized by a connecting cell cut off posteriolaterally from the fertilized carpogonium; 7) gonimoblast initial cut off laterally from one side of the auxiliary cell and giving rise to unilaterally branched gonimoblast filaments bearing carposporangia in branched chains; 8) gonimoblast fusion cell highly branched, candelabra‐like, incorporating all but the basalmost cells of the carposporangial chains and radiating through the central cells in the floor of the cystocarp; 9) spermatangial and tetrasporangial sori formed from surface cells in both monostromatic and polystromatic portions on both sides of the blade; and 10) tetrasporangia formed primarily from cortical rather than from central cells. The Schizoserideae presently includes Schizoseris Kylin, Neuroglossum Kützing, Abroteia J. Agardh, and Polycoryne Skottsberg in Kylin and Skottsberg.
POPULATION GENETICS AND TAXONOMY OF CAULERPA (CHLOROPHYTA) FROM THE GREAT BARRIER REEF, AUSTRALIA1
Authors: Benzie John A. H. , Price Ian R. , Ballment Elizabeth
Published: October 2004

Allozyme variation was examined in seven species and four varieties of Caulerpa sampled from the Great Barrier Reef (GBR) region, Australia. Differences between species were greater than those between populations of the same taxon sampled from different geographical locations, and typically included fixed gene differences (no alleles found in one taxon shared by the other taxon) at two or more loci. Three varieties of C. racemosa, vars imbricata, laetevirens, and racemosa, and a peltate morph of C. racemosa were as strongly distinguished genetically as the six other species examined: C. cupressoides, C. lentillifera, C. peltata, C. serrulata, C. sertularioides, and C. taxifolia. Cluster analysis did not place all of the C. racemosa varieties together and linked them with other species, but cladistic analyses showed the allozyme data gave little useful phylogenetic information. Eight of 13 plants identified initially as C. serrulata were distinguished at several loci, indicating the presence of an undetermined cryptic taxon. Population genetic analysis of polymorphism, which occurred in some taxa, demonstrated strong spatial differentiation among populations of C. cupressoides, C. racemosa vars laetevirens and racemosa, C. serrulata, and C. taxifolia and significant but variable degrees of clonality and/or inbreeding within these populations. Allozymes proved to be a useful tool for defining species boundaries and investigating population structure in Caulerpa, but not for determining phylogenetic relationships within the genus.
PHYLOGENETIC RELATIONSHIPS OF SELECTED EUGLENOID GENERA BASED ON MORPHOLOGICAL AND MOLECULAR DATA1
Authors: Montegut‐Felkner Ann E. , Triemer Richard E.
Published: October 2004

The small subunit rRNA (SSU rRNA) coding regions sequenced from the euglenoids Petalomonas cantuscygni, Peranema trichophorum, and Khawkinea quartana were used to assess the phylogenetic relationships of these genera within the Euglenozoa. Phylogenies derived from distance, parsimony, and maximum likelihood methods infer that the euglenoids and kinetoplastids form sister clades within a monophyletic assemblage. Distances representative of closely related lineages separate the genera within the Kinetoplastida, whereas larger distance values separate genera within the euglenoid assemblage. The results of the morphological and molecular studies suggest that phagotrophy arose early in the euglenozoan lineage with the subsequent acquisition of phototrophy, osmotrophy, and parasitism. Phagotrophic euglenoids with a pellicle composed of longitudinal strips appear to have diverged prior to genera with helically arranged strips. This study suggests that the hypothetical ancestor to the Euglenozoa was a phagotroph with two flagella, both containing paraxonemal rods. Furthermore, its basal bodies contained proximal cartwheels, were connected by a prominent fiber, and were anchored with three asymmetrically arranged flagellar roots.
DIRECT ENUMERATION OF BACTERIA FROM MACROALGAE BY EPIFLUORESCENCE MICROSCOPY AS APPLIED TO THE FLESHY RED ALGAE KAPPAPHYCUS ALVAREZII AND GRACILARIA SPP. (RHODOPHYTA)1
Authors: Largo Danilo B. , Fukami Kimio , Adachi Masao , Nishijima Toshitaka
Published: October 2004

This report describes a simplified method for direct counting of total bacteria associated with the fleshy red algae Kappaphycus alvarezii (Doty) Doty and Gracilaria spp. A Nuclepore® polycarbonate membrane (0.2–μm pore size) fitted to a vacuum filtration apparatus was used to filter algal tissue homogenate after serial dilution and staining with the fluorochrome 4′,6‐diamidino‐2‐phenylindole. Using epifluorescence microscopy, it is possible to count bacteria without preseparating them from the algae. The technique requires homogenized algal tissue diluted with 0.2‐μm‐filtered, autoclaved seawater to a level appropriate for counting. Dilution reduces the amount of autofluorescent algal debris, which may interfere with Counting. The membrane filtration method yielded a bacterial count two orders of magnitude higher than that of the conventional agarspread plate technique. This method offers a more accurate approach to counting the total number of bacteria on macroalgae.
FACTORS AFFECTING SURFACE ALKALINE PHOSPHATASE ACTIVITY IN THE BROWN ALGAFUCUS SPIRALISAT A NORTH SEA INTERTIDAL SITE (TYNE SANDS, SCOTLAND)1
Authors: Hernández Ignacio , Christmas Martin , Yelloly Julia M. , Whitton Brian A.
Published: October 2004

Surface alkaline phosphatase activity (APA) was measured in the tips ofFucus spiralisL. thalli over an approximately 1‐year period, using small plants from upper littoral rock pools at a site on the east coast of Scotland. Maximum APA (4.4 μmol p‐NP·g dry wt−1·h−1) occurred in April, coincident with a sharp increase in tissue N:P ratio of the tips and the probable period of most rapid growth. Enzymatic activity was not correlated with any of the physical and chemical factors (temperature, pH, external phosphate, salinity) measured in the pools or nutrient concentrations (C, N, P) in the apical part of the thallus. No obvious correlation was found between APA and the position of a plant on the shore. However, APA was significantly higher in plants emersed at low tide than in plants submerged during the whole tidal cycle. There was a significant positive correlation between APA and tissue P within a single thallus, with the highest value at the tip (which includes the meristematic zone). Changes in APA ofFucus spiralisappear to result from a complex interaction of biotic and environmental factors, including stress by emersion, growth period, rapid changes in tissue nutrient content and N:P ratio, and regzon of thallus.
AKINETE FORMATION IN PLANKTONIC ANABAENA SPP. (CYANOBACTEFUA) BY TREATMENT WITH LOW TEMPERATURE1
Authors: Li Renhui , Watanabe Masayuki , Watanabe Makoto M.
Published: October 2004

The effects of temperature, light intensity and nutrient depletion on akinete formation in seven strains of planktonic Anabaena spp.: A. mucosa TAC426; A. crassa TAC436; A. spiroides TAC443 and TAC444; A. flosaquae TAC446; and A. ucrainica TAC448 and TAC449 were examined. A Marked Pfft of temperature on akinete formation was observed at 40 μmol photons·m−2·sec−1 and nutrient‐sufficient conditions. At 20° C, akinetes did not develop in A. mucosa TAC426, A. crassa TAC436, A. spiroides TAC443, A. flos‐aquae TAC446, or A. ucrainica TAC449 but were formed at frequencies of a little over 11% (ratio of filaments with akinetes to total filaments) in A. spiroides TAC444 and A. ucrainica TAC448. None of the strains fmd akinetes or heterocysts at 30° C and 35° C. At lower temperature (10° C and 15° C), akinetes developed in all the strains at maximum frequencies of 13.4–77.4% during the late exponential phase or late exponential to stationary phases of growth. With only one exception, low light or nutrient deletion did not lead to the induction of akinete diferentiation at 20° C. Only akinete formation in A. flosaquae TAC446 was induced by nitrogen deletion with a frequency of 12.1%, similar to that induced by low temperature, but the initiation of akinete formation in the strain was delayed compared to treatment with low temperature. These results show that temperature was the most important environmental factor triggering akinete formation in these species. In A. crassa TAC436 and A. spiroides TAC443 and TAC444, akinetes developed during the late exponential growth phase even though heterocysts were formed at a 100% frequency (ratio of filaments with heterocysts to total filaments) throughout the entire growth phase. In A. mucosa TAC426, A. flos‐aquae TAC446, and A. ucrainica TAC448 and TAC449, there was a positive correlation between heterocyst and akinete formation, suggesting that the presence of a heterocyst may play a role in akinete formation.
ADSORPTION AND UPTAKE OF COPPER BY THE GREEN ALGA SCENEDESMUS SUBSPICATUS (CHLOROPHYTA)1
Authors: Knauer Katja , Behra Renata , Sigg Laura
Published: October 2004

Copper (II) accumulation has been investigated in the green alga Scenedesmus subspicatus G. Brinkmann considering both adsorption and uptake kinetics. Experiments were conducted in a Cu‐ and PH‐buffered medium at different free Cu2+ concentrations that were neither growth limiting nor toxic. We distinguished between adsorption on the cell surface and intracellular uptake by extracting copper from the cells with EDTA. Data from short‐term experiments were compared with data obtained from experiments under steady state conditions. The accumulation of Cu can be described by two processes, an initial fast adsorption occurring within a minute followed by a slower intracellular uptake. Metal uptake followed Michaelis‐Menten kinetics and is mediated by two systems, one with low and the other with high affinity. The maximum uptake rates (1.30 × 10−‐10 mol·[g dry wt algae]−1· min−1, 3.67 × 10−‐9 mol·[g dry wt algae]−1·min−1), and the half‐saturation constants (6.84 × 10−‐14 M, 2.82 × 10−‐12 M) for the two uptake systems were determined using the Lineweaver‐Burk plot. The calculated maximum concentration of binding sites on the surface of the algae is initially higher (9.0 × 10−‐6 mol Cu.[g dry wt algae]−1) than under steady state conditions (2.9 × 10−‐6 mol Cu·[g dry wt algae]−1). This suggests that the initial binding to the algal surface comprises the binding to specific transport ligands as well as to inert adsorption sites. The conditional stability constant of the Cu binding to surface ligands was calculated as log KCu= 11.0 at pH 7.9. This freshwater alga has a high ability to accumulate Cu, reflecting its adaptation to the bioavailable concentration of copper.
AN UNUSUAL PHYCOCYANOBILIN‐CONTAINING PHYCOERYTHRIN OF SEVERAL BLUISH‐COLORED, ACROCHAETIOID, FRESHWATER RED ALGAL SPECIES1
Authors: Glazer Alexander N. , Chan Crystal F. , West John A.
Published: October 2004

The reproductive biology and phycobiliproteins of four different culture isolates of the freshwater algaeAudouinellaand‘Chantransia’were investigated.‘Chantransia’sp. (3585/UTEX 2623) and Audouinella macrospora (Wood) Sheath et Burkholder (3394,3395) from California and Minnesota reproduced only by monospores. However, A. macrospora (3603/Necchi 1) reproduced by monosporangia that formed successive generations of theAudouinellaphase, andBatrachospermumshoots developed from the basal and erect systems. The major light‐harvesting phycobiliprotein in all of these isolates was a phycocyanobilin‐containing phycoerythrin not previously detected in red algae or cyanobacteria. As in the commonly found R‐ and B‐phycoerythrins, Audouinella phycoerythrin had a native molecular mass of ∼ 240,000 and was made up of α, β, and γ subunits. Audouinella phycoerythrin carried two phycoerythrobilins on the α subunit; one phycourobilin, one phycoerythrobilin, and one phycocyanobilin on the β subunit; and one phycourobilin and two phycoerythrobilins on the γ subunit. With excitation at 495, 563, or 603 nm, the fluorescence emission peak ofAudouinellaphycoerythrin was at 626 nm, showing that phycocyanobilin was the terminal energy acceptor.
BICARBONATE UTILIZATION BY MARINE PHYTOPLANKTON SPECIES
Authors: Nimer Nabil A. , Iglesias‐Rodriguez M. Debora , Merrett Michael J.
Published: October 2004

The contribution of bicarbonate to total dissolved inorganic carbon (DIC) utilization was investigated using 18 marine phytoplankton species, including members of Bacillariophyceae, Dinophyceae, Prymnesiophyceae, and Raphidophyceae, under carbon‐replete or ‐limited conditions. Extracellular carbonic anhydrase (CA) was assayed as an indicator of extracellular CA‐catalyzed HCO−3 utilization. For some species, extracellular CA was constitutive, in others activity was detected under conditions of carbon limitation, and in others, even under carbon‐limited conditions, activity was not detected. In species without extracellular CA, direct HCO−3 uptake was investigated using a pH drift technique in a closed system, DIC measurements, and the use of the anion exchange inhibitor 4′4′‐diisothiocyanatostilbene‐2,2‐disulfonic acid (DLDS). Three of these species (Chaetoceros compressus, Thalassiosira pseudonana, and Glenodinium foliaceum) gave a pH drift not inhibited by DIDS, but cultures of Chrysochromulina kappa, Gephrocapsa oceanica, and Coccolithus pelagicus, in which DLDS inhibited DIC uptake, did not give a pH drift. This result shows that direct HCO3− transport may occur by an anion exchange‐type mechanism in some species but not others. Of the eighteen species investigated, only Heterosigma akashiwo did not have the potential for direct uptake or extracellular CA‐catalyzed HCO−3 utilization.
IN VIVO MEASUREMENT OF ACTIVE OXYGEN PRODUCTION IN THE BROWN ALGA FUCUS EVANESCENS USING 2′,7′‐DICHLOROHYDROFLUORESCEIN DIACETATE1
Authors: Collén Jonas , Davison Ian R.
Published: October 2004

Intracellular production of active oxygen in the brown alga Fucus evanescens C. Ag. was studied by measuring the capacity for in vivo conversion of 2′,7′‐dichlorohydrofluorescein diacetate (DCFH‐DA) to the fluorescent dye 2′,7′‐dichlorofluorescein (DCF), both in emersed and immersed seaweeds. Algae were incubated in seawater containing DCFH‐DA under a range of conditions, and it was also possible to load algae with DCFH‐DA and then follow subsequent DCF production in emersed tissue. DCF formation was linear for at least 2 h in both darkness and light, with the rate of formation increasing with the light level. DCF formation was temperature dependent. It also increased when algae were treated with H2O2 or methyl viologen (paraquat), which disrupts photosystem 1 electron transport and increases O−2 production. Exogenous catalase reduced in vivo DCF production, presumably by lowering cellular concentrations of H2O2. Hydrogen peroxide was released into the seawater by illuminated algae resulting in external dye conversion to DCF. However, this does not interfere with in vivo measurement of DCF by loaded, washed algae because DCF leakage appeared to be negligible. Internal DCF did not affect photosynthetic oxygen production relative to untreated controls. Overall, our data suggest that DCFH‐DA is a potentially very useful probe for studying active oxygen metabolism in seaweeds subjected to environmental stresses.
FEEDING IN PERANEMA TRICHOPHORUM REVISITED (EUGLENOPHYTA)1
Authors: Triemer Richard E.
Published: October 2004

Feeding in Peranema trichophorum (Ehrenberg 1838) Stein 1878 was first observed over a century ago, yet there is still contention over how the feeding apparatus is used in feeding. Using video microscopy and scanning microscopy, this study documents two types of feeding. Peranema may engulf prey cells whole. Immotile cells are preferred, but moving cells occasionally are engulfed. Details of the early stages of engulfment are presented using scanning electron microscopy. A second method of feeding begins with the attachment of Peranema to a prey cell. The rods of the feeding apparatus then are repeatedly scraped over the surface of the prey until a tear occurs in the cell. The feeding apparatus is inserted into the opening and the internal cell contents are sucked out. The anterior flagellum is inserted into the prey to help remove the cell's contents.