Menu▼
NWT Publications / Individual Pubs ...
Books on a shelf

Vertically challenged: How disease suppresses Daphnia vertical migration behavior, 2017


Johnson, P.T., Stanton, D.E., Forshay, K.J., Calhoun, D.M.


Limnology and Oceanography
DOI: 10.1002/lno.10676
NWT Accession Number: NWT2003

Abstract

Parasitic infections are increasingly recognized as influential forces in the migratory behaviors of hosts ranging from butterflies to whales. In aquatic zooplankton, diel vertical migrations (DVMs) are among the most recurrent behaviors with implications for predator-prey interactions, nutrient cycling, and energy flow, yet how parasitism affects such migrations remains an open question. Here, we tested the effects of sporangia cluster disease (SCD) on DVM of the large-bodied Daphnia pulicaria, which is often considered a key component of lake food webs. By collecting depth-specific zooplankton samples across diel cycles, between years, and among lakes, we show that infection is associated with strong inhibition of host DVM; while all Daphnia tended to occur deeper during the day, uninfected Daphnia and especially gravid individuals migrated to shallower waters at night. In contrast, infected hosts—which could comprise 40% of the population—were more likely to remain deep regardless of time of day. Among infected hosts, the intensity of SCD (sporangia count per host) predicted the degree of DVM inhibition. These observations—coupled with lab-based assays showing that infected hosts exhibited fewer swimming movements and persisted at lower depths than uninfected conspecifics—suggest that parasite-induced inhibition of DVM is a “sickness behavior” resulting from increasing morbidity and energy depletion as the infection intensifies toward host death. Considering the importance of large-bodied Daphnia as regulators of water clarity and prey for fishes, parasite-induced alterations of host migratory behavior have broad potential to affect the redistribution of energy and nutrients within lake ecosystems.

Associated Niwot LTER Researchers:

Related Field Location(s):

Outside study area

Related Data by Discipline(s):

Limnology

Citation

Johnson, P.T., Stanton, D.E., Forshay, K.J., Calhoun, D.M., (2017) Vertically challenged: How disease suppresses Daphnia vertical migration behavior. Limnology and Oceanography , DOI: 10.1002/lno.10676

Instaar
Instaar
NSF
CU Boulder

This material is based upon work supported by the National Science Foundation under Cooperative Agreement #DEB-1637686. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necesarily reflect the views of the National Science Foundation.

Please contact lternwt@colorado.edu with questions, comments, or for technical assistance regarding this website.

Content

Main Menu

Home Location Flora/Fauna Research Data Publications Outreach Personnel

Utilities

News Links Contact PI login