Sarah Hensley '08
:
Strong ecological dependency on aquatic plants by invertebrates contributes to the ongoing global
distribution of exotic species. A highly fecund South American snail, Pomacea
insularum,epitomizes an exotic invasive species (EIS) that warrants serious concern. Colocasia
esculenta (wild taro), Eichhornia crassipes (water hyacinth) and Myriophyllum
spicatum (Eurasian water milfoil) represent highly successful EIS aquatic macrophytes whose ranges
often overlap with P. insularum. To investigate interactions between these species, we adapted
a field experiment to a nested design in the laboratory. We placed a single early (10 mm) or late (23 mm)
juvenile snail in one of 48 enclosures with three open compartments, each offering a different plant
(milfoil, wild taro or hyacinth). Twenty-four enclosures resided in a filtered pool containing crayfish
(Procambarus clarkii) and another 24 enclosures lacked crayfish. We recorded snail growth, individual
plant consumption rates (g dry plant mass per g blotted dry snail mass per day) and habitat preferences for
six weeks. Across all plant species, early juvenile snails consumed more plant matter per gram than late juveniles.
Snails readily consumed milfoil, followed by taro and then hyacinth. The combination of all three plants
allowed for 100% survival. Crayfish presence did not influence snail growth but sparked higher overall
consumption of plant resources, specifically Myriophyllum. Our study demonstrated that snails thrive
when fed exotic plants that several studies denote as poor quality resources. Consequently, such plants
may play an important role in sustaining reproductive populations and increasing invasive potential
and subsequent damage to new environments.
Sarah's Research Highlighted on NABS Poster
Research Summary:
This paper will soon appear in The Journal of Molluscan Studies!
Where I've been and Where I'm going:
Sarah now spends her time as a a Ph.D. candidate (4th year)
at the University of Amherst, Massachusetts in Microbiology. She updates:
"I'm currently working on adapting microbial cultures to fuel cell electrodes in order to
enhance power production. We did this by taking marine sediments and utilizing a poised
electrode to select for those bacteria (predominantly Geobacteraceae) that are able to reduce
the anode efficiently. These fuel cells could be used to power any electronics that are
hard to power, such as deep sea monitoring equipment."