Date of Award

Summer 7-23-2015

Degree Type


Degree Name

Master of Science in Integrative Biology (MSIB)



Committee Chair/First Advisor

Dr. William Ensign

Major Professor

Dr. Troy Mutchler

Second Committee Member

Dr. Jared Taglialatela


Mesograzers have the ability to greatly mitigate the effects of eutrophication in seagrass systems. In this study we look at pinfish (Lagodon rhomboides Linnaeus) as a potential epiphytic grazer and assess feeding preferences during a transitional stage in the ontogenetic diet shift exhibited by these fish. Since pinfish are abundant in seagrass meadows in the northern Gulf of Mexico, their dietary preferences have the potential to greatly impact seagrasses in this system. Twenty-four hour feeding trials were conducted to determine pinfish preference between seagrass (Thalassia testudinum) and algal epiphytes. St. Joseph Bay, FL was also surveyed to determine areas within this ecosystem that could be highly impacted by pinfish abundance. Significant spatial patterns were found among pinfish, as well as urchins and invertebrates, suggesting that some areas might be experiencing stronger grazing pressures. Feeding trials support previous studies showing that pinfish consume little to no T. testudinum and spatial patterns within St. Joseph Bay support past research showing that S. filliforme is a preferred seagrass for pinfish. Data regarding epiphytes as a preferred food source were inconclusive, as variation was high among treatments; further study is required.