Persistent, vertical-migration rhythms in benthic microflora.: II. Field and Laboratory Studies On Diatoms From The Banks Of The River Avon

Round, F. E.; Palmer, John D.

doi:10.1017/s0025315400017641

Cited by 131 publications

(100 citation statements)

References 13 publications

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“…In favourable conditions (such as low light) at time t i , microalgae continue to accumulate in the surficial layers, reaching maximum concentrations typically within 1-2 h. This finding apparently agrees with the results of Round & Palmer (1966) who reported that a 2-h period of light exposure was required before biofilm formation. The acceleration often observed in surface biomass accumulation when the light was switched on (e.g.…”

Section: Biofilm Formationsupporting

confidence: 90%

Endogenous versus environmental control of vertical migration by intertidal benthic microalgae

Coelho

Vieira

Serôdio

2011

European Journal of Phycology

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The vertical migratory behaviour of estuarine microphytobenthos, i.e. the biofilm-forming microalgae inhabiting intertidal sediments, is probably a significant factor for their success in this extreme and unstable environment. The present work aimed to assess the relative role of endogenous versus environmental control of benthic microalgal vertical migratory behaviour. This was done by comparing the patterns of vertical migration in undisturbed sediment samples kept under constant conditions of darkness and low light with those in ambient light conditions, by measuring the changes in the surface microalgal biomass during daytime low-tide periods. The results showed that the formation of a biofilm was a two-phase process. It began with a relatively small accumulation of cells at the surface, starting hours before the beginning of the light period and endogenously driven. However, the full formation of the biofilm required exposure to light by the expected beginning of the photoperiod, which further promoted upward migration and accelerated the cell accumulation at the surface. In the absence of light, upward migration was interrupted and the incipient biofilm began to disaggregate. The relative importance of the endogenously controlled behaviour varied during the spring-neap tidal cycle, reaching a maximum on those days when low tide occurred in the middle of the day, suggesting its entrainment by the duration of light exposure on previous days. The regulation of the surface cell concentration during daytime low tides was found to be strongly dependent on exogenous factors, particularly irradiance. The spontaneous disaggregation of the biofilm shortly before the end of the low-tide period (due to tidal flood or sunset), both under constant as well as ambient light conditions, suggested the presence of an endogenously controlled positive geotaxis.

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Section: Biofilm Formationsupporting

confidence: 90%

Endogenous versus environmental control of vertical migration by intertidal benthic microalgae

Coelho

Vieira

Serôdio

2011

European Journal of Phycology

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“…This is in agreement with the general observation that a minimum of light exposure is required for microalgae to move upwards (Round & Palmer 1966, Consalvey et al 2004b, Mitbavkar & Anil 2004.…”

Section: Variability In the Migration Pattern And Biofilm Constitutionsupporting

confidence: 92%

Does the size of the microphytobenthic biofilm on intertidal mudflats depend on the available photosynthetic biomass?

Herlory¹,

Blanchard²,

Planche³

et al. 2005

Mar. Ecol. Prog. Ser.

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“…Sequential patterns of migration of species to and from the surface have been seen in other studies from a range of different habitats (Round and Palmer 1966;Kingston 1999;Brotas et al 2003). There is also good evidence that microphytobenthic biofilms develop vertical structure with surface and subsurface layers of different taxa (Paterson et al 1998).…”

Section: Discussionmentioning

confidence: 61%

Patterns in microphytobenthic primary productivity: Species‐specific variation inmigratory rhythms and photosynthetic efficiency in mixed‐species biofilms

Underwood

Perkins

Consalvey

et al. 2005

Limnology & Oceanography

127

150

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The importance of temporal changes in the vertical distribution of microphytobenthic algae on the overall functioning of intertidal biofilms were investigated with low-temperature scanning electron microscopy and high-resolution single-cell fluorescence imaging of photosystem II efficiency (estimated by the fluorescence parameter F / Ј q F ) in intact cores maintained in tidal mesocosms. Early morning biofilms consisted of smaller naviculoid and Ј m nitzschioid taxa or euglenoid species. By midday, Gyrosigma balticum and Pleurosigma angulatum were dominant. Some taxa (e.g., Plagiotropis vitrea) disappeared from surface layers after midday. Species composition continued to change toward the end of the photoperiod, with G. balticum dominating in diatom-rich biofilms. In Euglena-rich biofilms, initial dense surface films of euglenids became progressively dominated by smaller diatoms. F /F (mea-Ј Ј q m sured at a photosynthetically active photon flux density (PPFD) of 220 mol m Ϫ2 s Ϫ1) of individual cells of all taxa declined significantly after midday, but increased toward dusk. There were significant differences in F /F between Ј Ј q m species, particularly after midday. F /F versus irradiance curves and relative electron transport rate (rETR max ) Ј Ј q m showed higher efficiencies and rETR max for euglenids, whereas G. balticum, Nitzschia dubia, and small Nitzschia sp. were shade-adapted with low values of F /F m Ј, rETR max , and E sat . G. balticum, P. vitrea, and N. dubia showed Ј q rapid vertical migration away from the surface with increasing irradiance. Euglenids, P. angulatum, and N. dubia exhibited their highest rETR max values at midday. E sat for algal cells was between 500 and 600 mol m Ϫ2 s Ϫ1 , except for N. dubia and small Nitzschia sp., which had an E sat of 300 mol m Ϫ2 s Ϫ1. Differences in behavioral and photophysiological traits between microphytobenthic taxa could be a form of niche separation and need to be incorporated into conceptual models of daily patterns of production in intertidal biofilms.

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Persistent, vertical-migration rhythms in benthic microflora.: II. Field and Laboratory Studies On Diatoms From The Banks Of The River Avon

Cited by 131 publications

References 13 publications

Endogenous versus environmental control of vertical migration by intertidal benthic microalgae

Endogenous versus environmental control of vertical migration by intertidal benthic microalgae

Does the size of the microphytobenthic biofilm on intertidal mudflats depend on the available photosynthetic biomass?

Patterns in microphytobenthic primary productivity: Species‐specific variation inmigratory rhythms and photosynthetic efficiency in mixed‐species biofilms

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