Student Research Projects

Potential Effects of Diet on Gizzard Shad Morphology

Student Ashley Wright
Faculty Mentor(s)
Department Biology
Course BIO 489: Research in the Natural Sciences


I am interested in doing a research project involving gizzard shad diet and morphology. I am currently examining the otoliths of gizzard shad from Florida lakes to determine age structure. Dr. Schaus, my advisor for the project, has already discussed with researchers from Cornell University, Miami of Ohio, and The St. Johns River Water Management District (Florida) that are willing to ship Gizzard Shad to us for this project from a total of 6 lakes.
I will be carefully dissecting out the intestinal tract, measuring its length and comparing it with their diets. Typically across species, the more nutritious the food source the shorter the intestines. Intestines are usually longer for poorer quality diets to absorb as much of the nutrients as is possible from the food source. My research would test whether this is true for gizzard shad across systems where they are more zooplanktivorous (Lake Oneida, NY) compared to systems where they are more detritivorous (Acton Lake, OH) or have a mixed diet (Lakes Denham, Apopka, Dora and Griffin, FL). The researchers sending the fish have more detailed information on their diets. Dr. Schaus would know which lake each fish came from, but I would not to make it a blind study and keep the data unbiased.
In addition to measuring their intestinal tracts, I am also formulating a way to measure the angle at which their mouth is to compare it with diet. The trend in most benthic feeders usually have a mouth tilted to the bottom and planktivorous fish have a more upward pointing mouth. The hypothesis is that the gizzard shad that are primarily detritvorous would have a mouth that is tilted down. If time is allows for it, I would also collect the otoliths to age the fish.


2009 VFIC Summer Undergraduate Science Research Fellowship