Foraging habits of Etheostoma caeruleum to determine dietary variability
Open Access
- Author:
- Mueller, Sara Jaye
- Area of Honors:
- Wildlife and Fisheries Science
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Jay Richard Stauffer Jr., Thesis Supervisor
Margaret C Brittingham, Thesis Honors Advisor - Keywords:
- Etheostoma
caeruleum
diet
foraging
niche
behavior
macroinvertebrate - Abstract:
- The objective of this study is to gain insight into the foraging habits of E. caeruleum in communities where there are varying degrees of competition with other benthic species including exotic Round Gobies. Fishes were collected from three populations, one from Woodcock Creek in Saegertown, Pennsylvania and two from Elk Creek in Erie, Pennsylvania. In Woodcock Creek four species of darter compete with the Rainbow Darter: Etheostoma zonale, Etheostoma variatum, Etheostoma blennoides, and Etheostoma flabellare. In Elk Creek at the, downstream site, Round Gobies, Neogobius melanostomus, are present although no other darter species are present. At the Elk Creek upstream site, there are no Round Gobies or other darter species present. Macroinvertebrate substrate samples were collected using a D-frame kicknet and the standard nine 30-second sampling technique. Fishes were collected with a 3 meter seine. Stomach contents of each fish were identified and analyzed to determine a difference in prey selection among the three populations. Principal component analyses and MANOVA tests were used to determine groups of similar prey selections among populations. Factor scores for principal component one were statistically different in comparisons between the Elk Creek upstream and Elk Creek downstream sites as well as between the Elk Creek upstream and Woodcock Creek sites. Factor scores for principal component two were statistically different in the comparison between the Elk Creek downstream and Woodcock Creek sites. From this we are able to conclude that there is a shift in darter diet when in competition with an exotic species, that there is a shift in darter diet when in competition with other darter species, and that the shift of diet is context dependent.