Meeting Abstract

P2.47  Sunday, Jan. 5 15:30  Morphology of the freshwater peritrich ciliate Scyphidia n. sp. in symbiotic pulmonate snails PERDICHIZZI, MS; University of Massachusetts, Lowell MaryAlice_Perdichizzi@student.uml.edu

Certain peritrich ciliates live as symbionts and associate with a variety of invertebrates. As bacterial filter-feeders, they may act as ectocommensals by attaching to the exposed surfaces of mobile invertebrate hosts like snails, small crustaceans, and fish. Some species of peritrich ciliate are also known to contain endosymbiotic green algae (Chlorella), a relationship that confers a mixotrophic benefit. In this research, I provide details on the morphology of a new Scyphidia species and its relationship to endosymbiotic Chlorella and its host pulmonate snails. To identify this ciliate species and understand its host specificity, scanning electron microscopy was used to reveal the surface placement of pores on the peristomial lip and pellicle. Dry silver nitrate staining was also used to measure the quantity of species-specific silverlines, and both DIC and brightfield imaging determined scopula width, macronucleus dimensions, and body size. I also set up experiments to determine if and how ciliates colonize new hosts. Ciliates were monitored for telotroch formation and dispersal after host death to determine host specificity and telotroch formation times. Details on the structure of the ciliate and its relationships to both the algal symbiont and host snails is provided.