ABSTRACT
Aim: This study deals with the distribution and ecology of euglenoids in relation to physicochemical characteristics of water in four lakes of Tumakuru district. Place and Duration of Study: Guluru, Bugudanahalli, Colony and Teeta are the four lakes of Tumakuru district selected for the present study during 2015-17. Methodology: Euglenoids function as indicators of aquatic superiority. Composite samples were taken at two feats depth from surface level on monthly basis for the enumeration of euglenoids. Results: A total of ten species under three genera were identified. Guluru lake harboured 46.66% followed by Colony and Teeta lakes 20% each and Bugudanahalli lake with 13.33%. Seasonally all the lakes recorded maximum density of euglenoids during summer except in Colony lake, where they reached their peak during rainy season. Euglenoids showed significant positive correlation with water temperature (r = 0.664: P < 0.05), Sulphate (r = 0.757: P < 0.05) and Silica (r = 0.775: P < 0.05) at 5% level. Conclusion: Euglenoids established negative correlation with dissolved oxygen and ammoniacal nitrogen. As the euglenoids serve as pollution indicator organisms, moderate density of euglenoids in the lakes investigated indicates that, lakes are tending towards biologically eutrophic condition.
ABSTRACT
This study provides valuable information on the ultrastructure and environmental conditions of the Trachelomonas Ehr. (Euglenophyceae) genus in the Guadalupe Dam, a eutrophic reservoir located in the suburbs of Mexico City, which receives a considerable volume of wastewaters. Specimens were collected at surface level between November 2005 and May 2006. Using LM and SEM twelve taxa from phytoplankton were identified of which, 9 are new records for Mexico. The reservoir is warm monomictic, with basic pH values (7.4-10.1), a high concentration of chlorophyll a (18-101 Ag l-1), a permanent anoxic bottom, specific conductivity (K25) of 205 to 290 AS cm-1, N-NO3 0.19-1.2 mg l-1 and P-PO4 0.22-1.6 mg l-1. Water temperature was 15.6-23.0oC. Most of the Trachelomonas species were found during the dry season, when concentrations of organic matter, nitrogen and phosphorus as well as the temperature were the highest. Higher species richness was also associated with the warmer months. This research contributes to increase our knowledge on Trachelomonas in Mexico and constitutes the first detailed description of lorica ultrastructure of 12 taxa that grow in a body of water with high concentration of nutrients and a moderate amount of mineral contents.