How it works

To determine Whether rotifers would show negative effects when ingesting toxic algae, we fed them one of the following six treatments: I. galbana (Ig) daily; A. andersoni (Aa) daily; one day Ig/two days Aa; one day Ig/ one day Aa; two days Ig/ one day Aa; and one day Ig/ one day unfed. Rotifers were fed their assigned diet over a five-day period.

Algae diets were replenished daily by filtering the treatment water out with an 80µm filter. We then filtered the rotifers using 0.2 filtered sea water, rinsed the beakers and poured the rotifers into a clean beaker. We then added the assigned algal diet treatment back to the beakers.

We used a flow cytometer to confirm rotifers were ingesting the algae and to determine whether they were selectively feeding on one or the other alga in mixed diet treatments. Twenty randomly chosen rotifers were examine to determine how many eggs they had produced (the eggs remain attached to the rotifer).