The Effect of Bead Concentration and Bead Size on the Clearance Rate of Brachionus plicatilus
Submission Type
Event
Expected Graduation Date
2015
Location
Center for Natural Sciences, Illinois Wesleyan University
Start Date
4-12-2014 2:00 PM
End Date
4-12-2014 3:00 PM
Disciplines
Biology
Abstract
Rotifers are small, free-swimming invertebrate animals found in freshwater and marine habitats. Their locomotion and feeding mechanisms involve the beating of cilia located on the corona. Rotifers consume various sizes of prey including bacteria, algae, and protozoans. We examined the effect of particle size and particle concentration on the feeding ability of the marine rotifer Brachionus plicatilus. Groups of rotifers were exposed to different concentrations of polystyrene beads (0.45 μm or 4.5 μm) for ten minutes. After incubation, the number of beads within the digestive system of each rotifer was counted using fluorescence (0.45 μm beads) and transmitted (4.5 μm beads) light microscopy. From these counts, we calculated the ingestion rates (beads/animal-hour) and clearance rates (mL of water cleared of particles/animal-hour). We found that the average clearance rates of 4.5 μm beads was significantly higher than the clearance rates of 0.45 μm beads (Mann-Whitney U, p = 0.05, n = 4). For 4.5 μm, particle concentration had a significant effect on clearance rate (Spearman’s, p < 0.005, r = -0.819).
The Effect of Bead Concentration and Bead Size on the Clearance Rate of Brachionus plicatilus
Center for Natural Sciences, Illinois Wesleyan University
Rotifers are small, free-swimming invertebrate animals found in freshwater and marine habitats. Their locomotion and feeding mechanisms involve the beating of cilia located on the corona. Rotifers consume various sizes of prey including bacteria, algae, and protozoans. We examined the effect of particle size and particle concentration on the feeding ability of the marine rotifer Brachionus plicatilus. Groups of rotifers were exposed to different concentrations of polystyrene beads (0.45 μm or 4.5 μm) for ten minutes. After incubation, the number of beads within the digestive system of each rotifer was counted using fluorescence (0.45 μm beads) and transmitted (4.5 μm beads) light microscopy. From these counts, we calculated the ingestion rates (beads/animal-hour) and clearance rates (mL of water cleared of particles/animal-hour). We found that the average clearance rates of 4.5 μm beads was significantly higher than the clearance rates of 0.45 μm beads (Mann-Whitney U, p = 0.05, n = 4). For 4.5 μm, particle concentration had a significant effect on clearance rate (Spearman’s, p < 0.005, r = -0.819).