Event Title

The Effect of Bead Concentration and Bead Size on the Clearance Rate of Brachionus plicatilus

Graduation Year

2015

Location

Center for Natural Sciences, Illinois Wesleyan University

Start Date

12-4-2014 2:00 PM

End Date

12-4-2014 3:00 PM

Description

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).

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Apr 12th, 2:00 PM Apr 12th, 3:00 PM

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).