Viruses as a Potential Food Source for the Brackish-Water Rotifer, Brachionus Plicatilis
Submission Type
Event
Expected Graduation Date
2015
Location
Center for Natural Sciences, Illinois Wesleyan University
Start Date
4-18-2015 2:00 PM
End Date
4-18-2015 3:00 PM
Disciplines
Biology
Abstract
Viruses are abundant within freshwater, saltwater, and brackish waters (~1×107 / mL). Consumption of bacteria (0.5-5 μm) by zooplankton has been studied, but few studies have addressed viruses (0.005-0.3 μm) as a possible source of diet. We studied the effects of viruses on survival and reproduction of Brachionus plicatilis, a brackish-water rotifer that feeds on algae, detritus, bacteria and protozoans. For each experiment, eighteen neonate rotifers (old) were each placed into an individual 2 ml well of a multiwell plate and were supplied with either viruses (5×106 cells / mL), algal cells (Nannochloropsis sp.; 1×105 cells / mL) or an equivalent volume of filtered seawater (starved controls); three times each day for a total 10 days the survival and reproduction of each rotifer was assessed. The experiment was replicated three times. Both survivorship and reproduction was greatest for rotifers fed Nannochloropsis (ANOVA; P < 0.05). The presence of viruses significantly (ANOVA; P < 0.05) increased the average reproduction and time reproducing (hrs) of rotifers when compared to starved controls. In contrast, the time (hrs) to first offspring was not significantly (ANOVA; P > 0.05) different between any of the treatments. Survivorship of rotifers varied across the three replicate experiments. Our data suggest that the viral particles contribute to a difference in reproductive output of rotifers that is not due to a survivorship limitation. These nonliving particles could serve as a source of nutrition for planktonic organisms and our results suggest an unrecognized, but prominent role of viruses in aquatic food webs.
Viruses as a Potential Food Source for the Brackish-Water Rotifer, Brachionus Plicatilis
Center for Natural Sciences, Illinois Wesleyan University
Viruses are abundant within freshwater, saltwater, and brackish waters (~1×107 / mL). Consumption of bacteria (0.5-5 μm) by zooplankton has been studied, but few studies have addressed viruses (0.005-0.3 μm) as a possible source of diet. We studied the effects of viruses on survival and reproduction of Brachionus plicatilis, a brackish-water rotifer that feeds on algae, detritus, bacteria and protozoans. For each experiment, eighteen neonate rotifers (old) were each placed into an individual 2 ml well of a multiwell plate and were supplied with either viruses (5×106 cells / mL), algal cells (Nannochloropsis sp.; 1×105 cells / mL) or an equivalent volume of filtered seawater (starved controls); three times each day for a total 10 days the survival and reproduction of each rotifer was assessed. The experiment was replicated three times. Both survivorship and reproduction was greatest for rotifers fed Nannochloropsis (ANOVA; P < 0.05). The presence of viruses significantly (ANOVA; P < 0.05) increased the average reproduction and time reproducing (hrs) of rotifers when compared to starved controls. In contrast, the time (hrs) to first offspring was not significantly (ANOVA; P > 0.05) different between any of the treatments. Survivorship of rotifers varied across the three replicate experiments. Our data suggest that the viral particles contribute to a difference in reproductive output of rotifers that is not due to a survivorship limitation. These nonliving particles could serve as a source of nutrition for planktonic organisms and our results suggest an unrecognized, but prominent role of viruses in aquatic food webs.