Event Title

The Effects of Increased Viscosity on the Ingestion and Clearance Rates of the Rotifer Species, Brachionus Plicatilis

Graduation Year

2015

Location

Center for Natural Sciences, Illinois Wesleyan Universtiy

Start Date

18-4-2015 2:00 PM

End Date

18-4-2015 3:00 PM

Description

Rotifers are a group of water-dwelling invertebrates that use rings of cilia located above and below the mouth to capture particulate foods. Brachionus plicatilis is a species commonly used as a food source for commercially-reared fish and normally consumes singled-celled algae (2-10 μm) as its food source. We examined the effect of sea water viscosity on the ingestion of 4.5 μm polystyrene beads by B. plicatilis. There are a variety ways to change the viscosity of a medium, this study introduces the sugar molecule dextran at a concentration of 150 mg mL-1 as a method of increasing the viscosity in order to determine how this would affect the ingestion rate (beads ingested per hour) and the clearance rate (milliliters of sea water ingested per hour) of B. plicatilis. The rotifers were transferred to clean filtered sea water for three hours to clear their digestive system before being exposed to polystyrene beads at a concentration of 7.5x103 beads mL-1 in 25OC filtered sea water or 25OC filtered sea water containing 150 mg mL-1 dextran. After a fifteen minute incubation period, the specimens were fixed and the number of beads within their guts were counted and converted into an ingestion rate and a clearance rate. In three separate experiments, we found no statistically significant difference (ANOVA, p > 0.05) between the ingestion and clearance rates of polystyrene beads by rotifers incubated in seawater of different viscosities. The clearance rates of B. plicatilis were not significantly affected by the increase in sea water viscosity, which was not expected based on what previous studies have shown. In these studies, the increase in viscosity tended to lead to a decrease in clearance rate, but those studies dealt with temperature fluctuations as opposed to the presence of a sugar. The results here could be explained by the use of a distinct particulate capturing mechanism by B. plicatilis that is more efficient at collecting particulates in more viscous solutions.

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Apr 18th, 2:00 PM Apr 18th, 3:00 PM

The Effects of Increased Viscosity on the Ingestion and Clearance Rates of the Rotifer Species, Brachionus Plicatilis

Center for Natural Sciences, Illinois Wesleyan Universtiy

Rotifers are a group of water-dwelling invertebrates that use rings of cilia located above and below the mouth to capture particulate foods. Brachionus plicatilis is a species commonly used as a food source for commercially-reared fish and normally consumes singled-celled algae (2-10 μm) as its food source. We examined the effect of sea water viscosity on the ingestion of 4.5 μm polystyrene beads by B. plicatilis. There are a variety ways to change the viscosity of a medium, this study introduces the sugar molecule dextran at a concentration of 150 mg mL-1 as a method of increasing the viscosity in order to determine how this would affect the ingestion rate (beads ingested per hour) and the clearance rate (milliliters of sea water ingested per hour) of B. plicatilis. The rotifers were transferred to clean filtered sea water for three hours to clear their digestive system before being exposed to polystyrene beads at a concentration of 7.5x103 beads mL-1 in 25OC filtered sea water or 25OC filtered sea water containing 150 mg mL-1 dextran. After a fifteen minute incubation period, the specimens were fixed and the number of beads within their guts were counted and converted into an ingestion rate and a clearance rate. In three separate experiments, we found no statistically significant difference (ANOVA, p > 0.05) between the ingestion and clearance rates of polystyrene beads by rotifers incubated in seawater of different viscosities. The clearance rates of B. plicatilis were not significantly affected by the increase in sea water viscosity, which was not expected based on what previous studies have shown. In these studies, the increase in viscosity tended to lead to a decrease in clearance rate, but those studies dealt with temperature fluctuations as opposed to the presence of a sugar. The results here could be explained by the use of a distinct particulate capturing mechanism by B. plicatilis that is more efficient at collecting particulates in more viscous solutions.