Habitat Ecology and Biological Characteristics of a Hypersaline Ciliate, Fabrea salina from Solar Salterns of Mumbai Coast, India

The ecology of a hypersaline ciliate, Fabrea salina was studied in two saltpans along the Mumbai coast, India. There was an apparent trend of its seasonal abundance being maximum (up to 58 x 103 cells L-1 in May) during late post- monsoon to summer months and complete disappearance during monsoon period. Being the most dominant species in microzooplankton community, it had an average annual density of 18 x 103 cells L-1. It flourishes well under higher temperature (30-39ºC) and salinity (40-150 ‰) conditions. Among phytoplankton, Dunaliella was the dominant one with a highest density of 58 x 103 cells mL-1 in April, followed by Chlorella with up to 42 x 103 cells mL-1, in March. The ANOVA test for physical and chemical variables has revealed significant difference (P=0.05) in their values in different months. Except in water temperature and NO2-N, no significant difference was observed at various stations as the case with phytoplankton and zooplankton. There was strong positive correlation of Fabrea with water temperature (r=0.866, 0.801), salinity (r=0.966, 0.957), total alkalinity (r=0.717, 0.729) and PO4-P (r=0.750, 0.897) while negative correlation with water depth (r=-0.767, -0.757) and pH (r=-0.086, -0.411). Fabrea varies widely in its total length (60-600 μm) and cyst diameter (70-180 μm). The average length of body cilia is 12 μm and the width of each adoral zone of membranelle (AZM) is 10 μm.