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Orlando Necchi - One of the best experts on this subject based on the ideXlab platform.

  • Photoacclimation in three species of freshwater red algae
    Brazilian Journal of Plant Physiology, 2007
    Co-Authors: Anna I.n. Bautista, Orlando Necchi
    Abstract:

    Tres especies de Rhodophyta continentais (Audouinella eugenea, A. hermannii e Compsopogon coeruleus) foram testadas em resposta a fotossintese, crescimento e concentracao de pigmento em dois niveis de irradiância (baixa irradiância, BI, 65 µmol m-2 s-1 e alta irradiância, AI, 300 µmol m-2 s-1) e dois periodos (curto periodo, CP, 4 d e longo periodo, LP, 28 d). Observaram-se maiores taxas de crescimento em BI, mas diferencas significativas foram encontradas apenas em A. hermannii. Observaram-se maiores valores de fotoinibicao em BI para as tres especies, consistentes com a dinâmica de fotoinbicao como um mecanismo fotoprotetor reversivel contra alta irradiância. Nas tres especies, verificou-se diminuicao induzida por luz no rendimento quântico efetivo, consistindo de forte queda de BI para AI. Aumentos rapidos de extincao nao-fotoquimica (NPQ) foram observados principalmente em BI, indicando dissipacao do excesso de energia pelos centros de reacao. Os resultados revelaram estrategias distintas de fotoaclimatacao para enfrentar altas irradiâncias: especies de Audouinella exibiram somente caracteristicas de algas adaptadas a sombra: aclimatacao por mudancas do tamanho das unidades dos fotossistemas (UF) sob LP e por numero de UF sob CP; valores maiores do parâmetro de fotoinibicao e NPQ e menores de rendimento quântico efetivo (RQE) em BI; maior capacidade de recuperacao de rendimento quântico potencial (RQP) em BI e sob CP; correlacao positiva altamente significante entre taxa relativa de transporte de eletrons (TTE) com NPQ. Compsopogon coeruleus apresentou caracteristicas de algas adaptadas ao sol: aclimatacao por mudancas no numero de UF sob LP e de tamanho de UF sob CP; maior capacidade de recuperacao de RQE; correlacao baixa ou nenhuma correlacao entre TTE e NPQ. Assim, estas caracteristicas indicam que C. coeruleus enfrenta altas irradiâncias mais eficientemente do que as especies de Audouinella.

  • Effects of temperature, irradiance and photoperiod on growth and pigment content in some freshwater red algae in culture
    Phycological Research, 2001
    Co-Authors: Marcelo Ribeiro Zucchi, Orlando Necchi
    Abstract:

    SUMMARY The responses of relative growth rate (% day‐1) and pigment content (chlorophyll a, phycocyanin and phycoerythrin) to temperature, irradiance and photoperiod were analyzed in culture in seven freshwater red algae: Audouinella hermannii (Roth) Duby, Audouinella pygmaea (Kutzing) Weber-van Bosse, Batrachospermum ambiguum Montagne, Batrachospermum delicatulum (Skuja) Necchi et Entwisle, ‘Chantransia’ stages of B. delicatulum and Batrachospermum macrosporum Montagne and Compsopogon coeruleus (C. Agardh) Montagne. Experimental conditions included temperatures of 10, 15, 20 and 25°C and low and high irradiances (65 and 300 µmol photons m‐2 s‐1, respectively). Long and short day lengths (16:8 and 8:16 LD cycles) were also applied at the two irradiances. Growth effects of temperature and irradiance were evident in most algae tested, and there were significant interactions among treatments. Most freshwater red algae had the best growth under low irradiance, confirming the preference of freshwater red algae for low light regimens. In general there was highest growth rate in long days and low irradiance. Growth optima in relation to temperature were species-specific and also varied between low and high irradiances for the same alga. The most significant differences in pigment content were related to temperature, whereas few significant differences could be attributed to variation in irradiance and photoperiod or interactions among the three parameters. The responses were species-specific and also differed for pigments in distinct temperatures, irradiances and photoperiods in the same alga. Phycocyanin was generally more concentrated than phycoerythrin and phycobiliproteins were more concentrated than chlorophyll a. The highest total pigment contents were found in two species typical of shaded habitats: A. hermannii and C. coeruleus. The expected inverse relationship of pigment with irradiance was observed only in C. coeruleus. In general, the most favorable conditions for growth were not coincident with those with highest pigment contents.

  • A new species and expanded distributions of freshwater Audouinella (Acrochaetiaceae, Rhodophyta) from Central Mexico and south-eastern Brazil
    European Journal of Phycology, 2001
    Co-Authors: Javier Carmona Jiménez, Orlando Necchi
    Abstract:

    Eighteen collections of red-coloured Audouinella from Central Mexico and southeastern Brazil detected three species. The most common species, A. eugenea, is characterized by macroscopic thalli, the erect system consisting of filaments with cylindrical cells, undifferentiated into proximal and distal parts, and relatively large monosporangia (≥12.0 µm long). Spermatangia and possible propagules were observed in some Mexican populations. This is the third Audouinella species observed to have gametangia and the first member of the Acrochaetiales with putative propagules. The second species, from Central Mexico, was characterized by the following features : macroscopic thalli, the erect system differentiated into proximal parts with cylindrical cells, unbranched or rarely branched, and distal parts with barrel-shaped cells, abundantly branched to form dense fascicles, with alternate or dichotomous branching, some at right-angles to the axis, and relatively large monosporangia (≥12.0 µm long). The morphologica...

  • Audouinella macrospora (Acrochaetiaceae, Rhodophyta) is the Chantransia stage of Batrachospermum (Batrachospermaceae)
    Phycologia, 1997
    Co-Authors: Orlando Necchi, Marcelo Ribeiro Zucchi
    Abstract:

    Abstract Twelve field and culture populations of freshwater acrochaetioid algae were examined to compare a bluish species of Audouinella, A. macrospora (Wood) Sheath et Burkholder, with the Chantransia stage of Batrachospermum and to test the validity of criteria used to distinguish freshwater Audouinella species from Chantransia. Six populations were identified as A. macrospora and six were unequivocally identified as Chantransia stages owing either to production of juvenile gametophytes of Batrachospermum attached to the apices of filaments or to derivation from Batrachospermum carpospores. In some populations, thalli initially identifiable as A. macrospora ultimately produced juvenile Batrachospermum gametophytes and therefore were reinterpreted as Chantransia. Because analysis of morphological variation (ANOVA) did not distinguish between populations of A. macrospora and Chantransia, all populations were concluded to be similar to one another and all are interpreted as Chantransia stages. Such thalli ...

  • Distribution of stream macroalgae in the eastern Atlantic Rainforest of São Paulo State, southeastern Brazil
    Hydrobiologia, 1996
    Co-Authors: Ciro Cesar Zanini Branco, Orlando Necchi
    Abstract:

    Fifty-two stream segments were sampled from 16 August to 13 September in 1993 in the eastern Atlantic Rainforest of São Paulo State, southeastern Brazil (22°55′–25°00′S, 44°48′–48°03′W). Forty-two macroalgal subgeneric taxa were found and the most widespread species were Audouinella pygmaea (21% of sites), Compsopogon leptoclados and Microcoleus subtorulosus (19%). Macroalgal species number per sampling site ranged from 0 to six (2.6 ± 1.7) and was positively correlated to species abundance, whereas species cover ranged from 0 to 70% of the stream bed (15.5 ± 20.8%). No significant correlation was found among macroalgal species number and abundance with any physical or chemical variable analyzed. Most sites were dominated by one or few macroalgal species, mainly, Audouinella macrospora, C. leptoclados and M. subtorulosus . No significant difference was found between the frequency distribution of variables measured for streams and for total macroalgae but the most widespread species ( A. pygmaea ) differed significantly for current velocity, specific conductance, turbidity and pH. Overall means for macroalgal occurrence include the following values: temperature (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 19.9°C), current velocity (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 45 cm s^−1), oxygen saturation (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 66%), specific conductance (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 59.6 µS cm^−1), turbidity (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 5 NTU) and pH (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 7.1). This pattern of patchy distribution and dominance by few species has been suggested as typical of stream macroalgal communities and has been ascribed to the rapid fluctuation of physical and chemical conditions. Total macroalgal species richness as well as mean species number per sampling site were considerably lower than found in similar studies of other regions. The Intermediate Disturbance Hypothesis was applied to explain these results: the same factor (high precipitation) responsible for the maintainance of the high species diversity in the surrounding forest can be, paradoxically, a constraint to the development of a more diverse macroalgal flora in streams.

Morgan L. Vis - One of the best experts on this subject based on the ideXlab platform.

  • Ottia meiospora (Ottiaceae, Rhodophyta), a new genus and family endophytic within the thallus of Nothocladus (Batrachospermales, Rhodophyta).
    Journal of phycology, 2017
    Co-Authors: Timothy J. Entwisle, Morgan L. Vis, Joshua R. Evans, Gary W. Saunders
    Abstract:

    A new genus, Ottia, and family, Ottiaceae, are proposed within the Acrochaetiales to accommodate the uniseriate red algal endophyte of batrachspermalean taxa previously named Balbiania meiospora. Prior to this study, Balbiania investiens was transferred to its own family and order (Balbianiales) based on comparative DNA sequence data and a distinctive reproductive morphology. However, the second species described in this genus, B. meiospora, continued to be treated as a species of Audouinella (A. meiospora) pending further investigation. Phylogenetic analyses of sequence data confirmed only a distant relationship between the two endophytes, and a closer alliance of B. meiospora to Acrochaetiales. The data also showed that Ottia meiospora was the deepest diverging lineage in the Acrochaetiales, sister to all of the currently recognized genera and families. In this study, we review the classification of what we now call O. meiospora - reported from Australia, New Zealand and Brazil - based on sequence and morphological data. Morphological observations provided little clarity around the reproductive morphology or the life cycle of this endophyte of Nothocladus s. lat. found commonly in mainland Australia but, to date, less so in New Zealand.

  • Photosynthetic characteristics of some common temperate freshwater red algal taxa (Rhodophyta)
    Phycologia, 2015
    Co-Authors: Samuel A. Drerup, David A. Gonzalez, Morgan L. Vis
    Abstract:

    Abstract: We measured photosynthetic–irradiance curves of freshwater red algae in the Batrachospermales and Acrochaetiales from five low-order streams with one to five taxa collected from each stream in the central portion of the Ohio River basin. Four populations of Batrachospermum helminthosum, two populations of B. gelatinosum and Audouinella hermannii and one population of Batrachospermum sp. and Tuomeya americana were sampled. All five species of freshwater red algae were found within a single stream. We observed two distinct groups of algae from this stream: a low photosynthetic efficiency/high initial saturation group and a high photosynthetic efficiency/low initial saturation group distinguished by morphology. Mucilaginous forms, such as B. helminthosum, had significantly greater maximum photosynthesis and efficiency compared to those of the more “tuftlike” or compact morphology, such as A. hermannii. Photosynthetic responses of B. helminthosum in four streams showed a positive relationship with m...

  • Ptilothamnion richardsii (Rhodophyta) is a chantransia stage of Batrachospermum
    European Journal of Phycology, 2006
    Co-Authors: Morgan L. Vis, John A. West, Timothy J. Entwisle, Franklyn D. Ott
    Abstract:

    Four specimens attributable to the freshwater red algal taxon, Ptilothamnion richardsii, were examined from locations in Australia and French Guiana, and partial rbcL gene sequence data were obtained. Phylogenetic analyses showed these specimens to be allied to taxa in the Batrachospermales. The two specimens from Australia were determined to be Batrachospermum antipodites, differing from that taxon by only 15 bp (1.2%). The two specimens from French Guiana were within the Batrachospermum section Contorta clade, but differed considerably (≥8%) from the taxa for which there are presently rbcL gene data. The sequence data clearly show these specimens to be chantransia stages of Batrachospermum taxa. Recently, other described freshwater Audouinella taxa have also been shown to be chantransia stages. Like previous authors, we argue that it is useful to continue to recognize entities with particular morphological characters and propose the form taxa Chantransia richardsii, C. macrospora and C. pygmaea. A key t...

  • Phenology of Paralemanea annulata (Lemaneaceae, Rhodophyta) in an Ohio woodland stream
    Hydrobiologia, 2004
    Co-Authors: Nanda R. Filkin, Morgan L. Vis
    Abstract:

    Paralemanea annulata , a member of Lemaneaceae (Batrachospermales, Rhodophyta) was investigated in a field study to monitor its seasonality and determine environmental parameters that play a role in its phenology. Macroscopic gametophytes were present during the months of December–August, and percent cover dropped precipitously from June to July. Thalli had spermatangia present in all months except December and carposporophytes were observed in May and June. Audouinella hermannii thickly colonized the thalli March–June. Lack of thalli from September–November corresponded with low water and increased water temperature. New growth of gametophytes was first observed in December. Gametophyte percent cover showed a positive correlation with both current velocity and light intensity. A laboratory study was conducted in the winter and spring, which investigated growth in relation to temperature, daylength and light intensity. Thalli grew more slowly in the 5 °C treatments than the 15 °C treatments and no clear trends could be determined among the daylength and light intensity treatments. For all treatments, thalli grew more in the winter than the spring experiment.

  • Phenology ofLemanea fucina (Rhodophyta) in a Rhode Island river, USA
    Hydrobiologia, 1991
    Co-Authors: Morgan L. Vis, Tracy A. Carlson, Robert G. Sheath
    Abstract:

    In a fourth-order river in Rhode Island, USA, cover, frequency of occurrence, length and node number of the red alga Lemanea fucina were greatest in July and August, at which time current velocity and water depth were minimum and temperature was maximum. Population abundance and plant size were lowest in fall-early winter. The length of reproductive region and carpospore frequency were also highest in June to August, whereas percent plants with open tips was least in July and highest in February. It appears that growth and reproduction are confined to a period from April to August, after which there is thallus deterioration and carpospore release; between September and March remnants of this population remain. Lemanea plants are epiphyte-free from September to January. Subsequently, they are colonized by caddisflies and then the red alga Audouinella violacea ; by August, 100% of the Lemanea plants are covered by Audouinella .

Antonio Flores-moya - One of the best experts on this subject based on the ideXlab platform.

José C. Báez - One of the best experts on this subject based on the ideXlab platform.

John A. West - One of the best experts on this subject based on the ideXlab platform.

  • Nomenclatural changes for some freshwater red algae from India
    ALGAE, 2013
    Co-Authors: E. K. Ganesan, John A. West
    Abstract:

    In preparing a bibliographic check-list on freshwater red algae of India, we noted that nomenclatural changes are necessary for nine taxa currently placed in Acrochaetium-Audouinella-Chantransia complex and Batrachospermum sensu lato. These are Audouinella desikacharyi nom. nov., A. keralayensis (Jose & Patel) comb. nov., Kumanoa balakrishnanii (Chaugule) comb. nov., K. dasyphylla (Skuja ex Balakrishnan & Chaugule) comb. nov., K. iyengarii (Skuja ex Balakrishnan & Chaugule) comb. nov., K. kylinii (Balakrishnan & Chaugule) comb. nov., K. mahabaleshwarense (Balakrishnan & Chaugule) comb. nov., K. umamaheswararaoi (Baluswami & Babu) comb. nov., and K. zeylanica (Skuja ex Balakrishnan & Chaugule) comb. nov. All the above-mentioned species, excepting Kumanoa zeylanica, appear to be endemic to India, since no other records are known outside India.

  • Ptilothamnion richardsii (Rhodophyta) is a chantransia stage of Batrachospermum
    European Journal of Phycology, 2006
    Co-Authors: Morgan L. Vis, John A. West, Timothy J. Entwisle, Franklyn D. Ott
    Abstract:

    Four specimens attributable to the freshwater red algal taxon, Ptilothamnion richardsii, were examined from locations in Australia and French Guiana, and partial rbcL gene sequence data were obtained. Phylogenetic analyses showed these specimens to be allied to taxa in the Batrachospermales. The two specimens from Australia were determined to be Batrachospermum antipodites, differing from that taxon by only 15 bp (1.2%). The two specimens from French Guiana were within the Batrachospermum section Contorta clade, but differed considerably (≥8%) from the taxa for which there are presently rbcL gene data. The sequence data clearly show these specimens to be chantransia stages of Batrachospermum taxa. Recently, other described freshwater Audouinella taxa have also been shown to be chantransia stages. Like previous authors, we argue that it is useful to continue to recognize entities with particular morphological characters and propose the form taxa Chantransia richardsii, C. macrospora and C. pygmaea. A key t...

  • Affinities of the freshwater red alga Audouinella macrospora (Florideophyceae, Rhodophyta) and related forms based on ssu rrna gene sequence analysis and pit plug ultrastructure
    Journal of Phycology, 2001
    Co-Authors: Curt M. Pueschel, Gary W. Saunders, John A. West
    Abstract:

    Small subunit rDNA sequencing and transmission electron microscopy were performed to clarify the ordinal affinities of Audouinella macrospora (Wood) Sheath et Burkholder isolates 3394, 3395, and 3603, as well as Chantransia sp. isolate 3585. Culture 3603 is known to produce thalli of Batrachospermum -like morphology under certain culture conditions. Sequence analyses unequivocally placed the three Audouinella macrospora isolates in a clade with Batrachospermum macrosporum Montagne of the Batrachospermales, and Chantransia sp. was found to have affinities with B. louisianae Skuja and B. virgato-decaisneanum Sirodot. The pit plugs of the Audouinella macrospora cultures 3394 and 3395 were nearly identical in size and structure, having thickened plug caps and no cap membranes. Both of these features agree with those of the Batrachospermaceae, with the latter feature showing batrachospermacean rather than acrochaetioid affinities. Pit plugs in the chantransia phase of 3603 were similar, but the plug caps were less well developed. The Batrachospermum phase generated from 3603 had pit plugs that were variable in diameter, according to location in the thallus, thus reflecting the more variable cell size in this phase. Dome-like outer caps, considered typical of Batrachospermum, were present between cells of the determinate lateral filaments. The pit plugs of Chantransia sp. had prominent, dome-like outer caps, but the plug cores were strikingly and consistently smaller in diameter than those of the A. macrospora chantransia cultures, suggesting that plug diameter may be of systematic value in some contexts.

  • AN UNUSUAL PHYCOCYANOBILIN-CONTAINING PHYCOERYTHRIN OF SEVERAL BLUISH-COLORED, ACROCHAETIOID, FRESHWATER RED ALGAL SPECIES1
    Journal of Phycology, 1997
    Co-Authors: Alexander N. Glazer, Crystal F. Chan, John A. West
    Abstract:

    The reproductive biology and phycobiliproteins of four different culture isolates of the freshwater algae Audouinella and‘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 the Audouinella phase, and Batrachospermum shoots 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 of Audouinella phycoerythrin was at 626 nm, showing that phycocyanobilin was the terminal energy acceptor.