Yossi Shirazi - Marine & Estuarine Ecology
University of Maryland, College Park
Utilization of Microzooplankton by Adult Ctenophores:
Effects of Fecundity and Growth
The lobate ctenophore, Mnemiopsis leidyi, is a common and voracious planktonic predator in the western Atlantic Ocean. While these ctenophores feed primarily on mesozooplankton, their less significant grazing on microzooplankton is not well understood. Because M. leidyi is capable of reaching high densities in coastal waters, and their presence can regulate mesozooplankton communities, a robust understanding of their trophic dynamics will help guide coastal management and policy. My experiment determined the ability of adult ctenophores to utilize microzooplankton to fulfill their energy requirements for both growth and reproduction. A different microzooplankton density was added to two tanks, each containing 10 field-caught ctenophores, over a series of triplicate 4 –day lab experiments. The average initial weights of the ctenophores were compared to their final weights to obtain data on growth. For reproduction, ctenophores were isolated in jars during the last 24 hours of the experiment, after which the eggs were collected and counted. Our data showed that ctenophore growth ranged from near zero to -48%. Furthermore, egg production was evident in all ctenophores, but production rates on a per gram basis were far less than those found in the field.
The Future: After graduating in Spring 2007, I plan on traveling/working abroad in the aquaculture business. The following Fall I would like to start a graduate program in marine ecology or mariculture.
This research project was presented as a poster at the Atlantic Estuarine Research Society Fall 2006 Meeting at the Community College of Baltimore County in Catonsville, MD.
Funding provided by the National Science Foundation – Research Experience for Undergraduates (REU)