Impact of pH on Cell Morphometry of Scenedesmus abundans

Abstract

Global climate change is expected to dramatically impact the structure and function of freshwater aquatic ecosystems. Regional climate change in the upper and lower lake of Bhopal, India is expected to increase air and stream temperatures, modify hydrologic regimes, and increase the amount and frequency of disturbance events (debris flows, landfill, and human encroachment to the catchments area). These climatic changes combined with species-specific tolerances to regime extreme (e.g., pH variability) will likely result in significant changes in the distribution, abundance, and diversity of many aquatic species, particularly Scenedesmus species, a phenotypic plastic microalga. In the present study, the effect of pH on cell morphometry Scendesmus abundans var. brevicauda was investgated. In the low pH (below 5.0) range, no growth of Scenedesmus abundans var. brevicauda was detected and the measured cell dimensions were 6.Ox2.7µm.The coenobium became almost colourless and lost its obvious green colour. The cells were shrunken and perforated. The cells became quadratic in their outline. At the alkaline pH, the cell dimensions increased to 7.5x3.3µm with an increase in chlorophyll content.