Nivedita Moon Moon*
University Department of Zoology, Ranchi University, Ranchi, Jharkhand, India
Received : 15th June, 2021 ; Revised : 16th July, 2021
Abstract– For the study of the fundamental niche of Mesocyclops a common zooplankton species, Mesocyclops leuckartii (a cyclopoid copepod) was selected and then its fundamental niche was identified. The niche can only be conceptualized in freshwaters. Therefore for understanding the actual picture of the environmental conditions amoeba diagrams, defining the environmental parameters, of Ranchi Lake were created. Within the broad environmental framework, the three major parameters which define the fundamental niche of Mesocyclops are food resource, temperature and alkalinity. Mesocyclops population showed a significant negative correlation with the phytoplankton population. With increase in the Mesocyclops population there will be increased pressure on the food resource. Similarly, it showed a significant negative correlation with the temperature too. A decrease in the Mesocyclops population was observed below 16°C and an increase above 25°C. However, it showed a significant positive correlation with the alkalinity in the range of 200 – 250 mg L-1. The area of the fundamental niche changes during an annual cycle with changes in the respective parameters. At Ranchi Lake it was found that the fundamental niche had its greatest area (niche relaxation) in the month of May and smallest (niche compression) in the month of July.
Key words: Niche, Niche Relaxation, Correlation, Amoeba, Copepod