Identification of sessile ciliated protozoans and their impact on freshwater ostracods

Globally, fens are unique and relatively rare wetland systems that have been destroyed mostly for agricultural reasons, leaving only 2 % remaining. Ostracods are a regular but often overlooked component of fens and similar aquatic systems. Ostracods can serve as indicators of water quality in wetland systems because specific species have a low threshold survival to disturbance while others have a high threshold survival to disturbance. Sessile ciliated protozoans are a common epibiont of freshwater ostracods. Several studies have demonstrated that an increase in total phosphorus will cause an infestation of sessile ciliated protozoans on their crustacean host.;This research focused on the identification of ciliates in the family Lagenophryidae on three ostracods species (Candona neglecta, Cypridopsis okeechobei, and Physocypria globula.). The main objectives of this research were 1. To utilize electron microscopy techniques to identify the sessile ciliated protozoan's infesting the ostracods in fens. 2. To monitor infestation levels over a period of two years in order to evaluate the impact infestation is having on the ostracods. 3. To study the effects of phosphate on ostracods infestation rates. The use of electron microscopy has identified the protozoan as Lagenophrys discoidia. Long-term preliminary data suggest that the infestation of ostracods within Galvin and Sennert fens is increasing in intensity. Experiments conducted in the laboratory showed an increase in infestation rates with the addition of phosphates for samples collected from high quality fens.