The focus of the research is the nutritive processes of small hydromedusae. The large medusae that are so familiar in coastal waters because they are visible to the naked eye are important plankton predators that can strongly affect the numbers of zooplankton (microscopic marine animals) as well as fish eggs and larvae. The very small medusae that are the focus of the study are far more abundant than their larger relatives. In spite of their status as the largest and most diverse group of gelatinous zooplankton in the sea, the feeding ecology of small jellyfish is virtually unknown.
During the course of this project Gifford and colleagues will study small hydromedusae in Narragansett Bay, Rhode Island, to quantify the impact of the feeding ecology of the hydromedusae on the plankton community and to quantify when and what they are feeding on. It has been determined that hydromedusae are omnivorous, feeding on both very small zooplankton (microzooplankton) and phytoplankton (microscopic marine plants). Preliminary studies indicate that the small jellyfish are likely to represent a completely unexpected source of mortality on the spring phytoplankton bloom in northern coastal waters.
"This research will lead to new understanding of community feeding rates, prey selection patterns and the underlying feeding mechanisms that have led to the success and evolutionary longevity of the most diverse group of medusae," said Gifford. "The study will also provide evolutionary ecologists with a greater understanding of the biomechanical factors that have influenced the evolution of
Contact: Lisa Cugini
University of Rhode Island