Assessing algae survivorship following snail grazing.

Abstract

A study by Porter (1976) showcases planktonic chlorophyta within the family of Sphaerocystis to be the best at surviving digestion by grazers due to presence of a complicated polysaccharide sheath found on the cells. This sparked interest in studying the survivorship of different algal groups after undergoing digestion by a two species of grazing snails (Physa sp. and Lymnaea sp.). Fecal samples were carefully examined to identify the cells and their abundance in order to compare a digested sample of algae to one uneaten. We hypothesized that cyanobacteria will have the highest survivorship amongst the algae groups due to the presence of a mucous membrane. Our results show a shift in the total cell distribution following digestion. Physa sp. had ~79% of the overall bacillariophyceae cells from the uneaten algae sample in the fecal sample, with an increase of ~580% for cyanobacterial cells and an increase of ~88% for chlorophyta. Bacillariophyta for Lymnaea sp. decreased to ~68% compared to the original uneaten algae sample along with an increase of ~492% for cyanobacteria and an increase of ~150% for chlorophyta. We learned that cyanobacteria had the highest survivorship.