Morphological variability of Aulacoseira granulata (Ehr.) Simonsen (Bacillariophyceae) in the Lower Paraná River (Argentina)

In this paper we consider the morphological variation within a natural population of Aulacoseira granulata (Ehr.) Simonsen in relation to environmental factors. This species was dominant in the phytoplankton of the Lower Paraná River (Argentina) and exhibited seasonal fluctuations of cell dimensions...

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Publicado: 2001
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14398621_v2_n2_p65_OFarrell
http://hdl.handle.net/20.500.12110/paper_14398621_v2_n2_p65_OFarrell
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spelling paper:paper_14398621_v2_n2_p65_OFarrell2023-06-08T16:16:02Z Morphological variability of Aulacoseira granulata (Ehr.) Simonsen (Bacillariophyceae) in the Lower Paraná River (Argentina) Aulacoseira granulata Cell morphology Diatoms Phytoplankton South America diatom freshwater ecosystem morphology phytoplankton Argentina Parana River Aulacoseira granulata In this paper we consider the morphological variation within a natural population of Aulacoseira granulata (Ehr.) Simonsen in relation to environmental factors. This species was dominant in the phytoplankton of the Lower Paraná River (Argentina) and exhibited seasonal fluctuations of cell dimensions. The mean cell diameter was directly correlated with the river water level and inversely with pH and nitrate concentrations, whereas cell length was directly correlated with transparency and nitrate concentration and inversely with suspended solids. This pattern was similar to that observed for filament length. The cell length: Diameter ratio was inversely related to water level and discharge and directly related to pH, transparency, and nitrate concentration. Maximum diameters did not coincide with maximum lengths. A tendency to maintain cell volume throughout the annual cycle was observed, which probably relates to both buoyancy and photosynthetic capacity. These results associate the water ascendancy and the size recovery phases to discharge. Cells become smaller on the ebbing of the flood phase, and the decreasing depth increases the probability that the alga will be disentrained from the turbulent field. The loss during low water would act as a stimulus for auxosporulation, contributing to the production of large cells to start off the next population. 2001 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14398621_v2_n2_p65_OFarrell http://hdl.handle.net/20.500.12110/paper_14398621_v2_n2_p65_OFarrell
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Aulacoseira granulata
Cell morphology
Diatoms
Phytoplankton
South America
diatom
freshwater ecosystem
morphology
phytoplankton
Argentina
Parana River
Aulacoseira granulata
spellingShingle Aulacoseira granulata
Cell morphology
Diatoms
Phytoplankton
South America
diatom
freshwater ecosystem
morphology
phytoplankton
Argentina
Parana River
Aulacoseira granulata
Morphological variability of Aulacoseira granulata (Ehr.) Simonsen (Bacillariophyceae) in the Lower Paraná River (Argentina)
topic_facet Aulacoseira granulata
Cell morphology
Diatoms
Phytoplankton
South America
diatom
freshwater ecosystem
morphology
phytoplankton
Argentina
Parana River
Aulacoseira granulata
description In this paper we consider the morphological variation within a natural population of Aulacoseira granulata (Ehr.) Simonsen in relation to environmental factors. This species was dominant in the phytoplankton of the Lower Paraná River (Argentina) and exhibited seasonal fluctuations of cell dimensions. The mean cell diameter was directly correlated with the river water level and inversely with pH and nitrate concentrations, whereas cell length was directly correlated with transparency and nitrate concentration and inversely with suspended solids. This pattern was similar to that observed for filament length. The cell length: Diameter ratio was inversely related to water level and discharge and directly related to pH, transparency, and nitrate concentration. Maximum diameters did not coincide with maximum lengths. A tendency to maintain cell volume throughout the annual cycle was observed, which probably relates to both buoyancy and photosynthetic capacity. These results associate the water ascendancy and the size recovery phases to discharge. Cells become smaller on the ebbing of the flood phase, and the decreasing depth increases the probability that the alga will be disentrained from the turbulent field. The loss during low water would act as a stimulus for auxosporulation, contributing to the production of large cells to start off the next population.
title Morphological variability of Aulacoseira granulata (Ehr.) Simonsen (Bacillariophyceae) in the Lower Paraná River (Argentina)
title_short Morphological variability of Aulacoseira granulata (Ehr.) Simonsen (Bacillariophyceae) in the Lower Paraná River (Argentina)
title_full Morphological variability of Aulacoseira granulata (Ehr.) Simonsen (Bacillariophyceae) in the Lower Paraná River (Argentina)
title_fullStr Morphological variability of Aulacoseira granulata (Ehr.) Simonsen (Bacillariophyceae) in the Lower Paraná River (Argentina)
title_full_unstemmed Morphological variability of Aulacoseira granulata (Ehr.) Simonsen (Bacillariophyceae) in the Lower Paraná River (Argentina)
title_sort morphological variability of aulacoseira granulata (ehr.) simonsen (bacillariophyceae) in the lower paraná river (argentina)
publishDate 2001
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14398621_v2_n2_p65_OFarrell
http://hdl.handle.net/20.500.12110/paper_14398621_v2_n2_p65_OFarrell
_version_ 1768542855856390144