Popis: |
1 Universidad Nacional Autonoma de Mexico, Facultad de Ciencias,Departamento de Ecologia y Recursos Naturales, Mexico, D.F.2 Universidad Nacional Autonoma de Mexico, FES-Iztacala,Edo. de Mexico, Mexico.With 3 figures and 4 tables in the textAbstract: Microhabitat was investigated in four populations of B. ganeshii in calcareoustropical streams in central Mexico to determine fue distributional patterns and some oftheir controlling factors, as well as morphometric adaptations to varying conditions onscales of a few centimetres. Morphometric variations and their relation to physical vari-ables (current velocity, depth, irradiance, and type of substramm) revealed some character-istics for each population and indicated particular adaptations: current velocity was nega-tively correlated with filament length, filament diameter and trichome width; irradiancewas positively correlated with filament diameter and trichome width, number of falsebranches in a filament and percent cover; and predominant substramm was positively cor-related with filament length and sheath thickness. The information here reported about fueecological distribution of B. ganeshii supplements fue taxonomic knowledge with dataabout its environmental requirements, which are important for fue taxonomy of fue genus.Variations in microhabitat conditions and niche widths are the main contributors to fuewide spatial and seasonal distribution of this Oscillatorian in central Mexican streams.Key words: Blennothrix, central Mexico, Cyanobacteria, Cyanophyceae, ionic com-position, current velocity, irradiance, microhabitat, morphometric varia-tion, streams. |