The West Indian Sea Egg (Tripneustes ventricosus) can Learn to Eat the Invasive Seagrass Halophila stipulacea

Undergraduate #67
Discipline: Biological Sciences
Subcategory: Ecology

Kyle Jerris - University of the Virgin Islands
Co-Author(s): Teresa Turner, University of the Virgin Islands, St. Thomas USVI

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The West Indian Sea Egg (Tripneustes ventricosus) is one of the most prominent grazers on Caribbean seagrass beds. On some Caribbean islands such Martinique and St. Lucia, there is a commercial fishery for it. Because Caribbean seagrass beds are being invaded by the Indian Ocean seagrass Halophila stipulacea, a seagrass grazer like T. ventricosus would be a prime candidate to control it. This study conducted on St. Thomas United States Virgin Islands, aimed to determine whether Tripneustes can act as a biological control for Halophila as well as what effects this seagrass might have on the urchin. To test this hypothesis a multi-choice feeding experiment was conducted to determine preference among the seagrass species found on the island. The experiment showed that T. ventricosus preferred Thalassia testudinum over the other seagrasses but did not eat significantly more of the other native seagrass Syringodium filiforme. A no choice experiment was also conducted to determine feeding rate. The urchins ate more T. testudinum than the invasive seagrass even with no choice. To further determine if the West Indian Sea egg would be a suitable biocontrol for H. stipulacea, urchins were fed either Halophila or Thalassia for four weeks. After the four week, another multi-choice and no choice experiment was done. The data suggested that the urchins did learn to eat the invasive seagrass.

Funder Acknowledgement(s): NSF VI-EPSCoR

Faculty Advisor: Teresa Turner, tturner@uvi.edu

Role: I did every part of this research.