Alison Gould, an EEB graduate student in the lab of Professor Paul Dunlap, has been awarded a Rackham Predoctoral Fellowship. The fellowship supports outstanding doctoral students who have achieved candidacy and are actively working on dissertation research and writing.

Gould’s dissertation is titled, "The evolutionary ecology of a bioluminescent vertebrate-microbe symbiosis.” She is examining the population genetics of a bioluminescent symbiosis involving the coral reef cardinal fish, Siphamia tubifer, and the luminous bacterium, Photobacterium mandapamensis, in Okinawa, Japan. Symbiotic associations between fish and specific types of luminous bacteria are biologically important components of many marine ecosystems, and their persistence depends on their biological specificity. 

“I will define the fine-scale population genetic structure of both symbiotic partners to determine the role of the host fish in maintaining symbiont specificity over time,” Gould said. 

“Understanding how specificity arises and is maintained is especially important now, as changes in the marine environment, such as increases in sea surface temperature and acidification, are occurring more rapidly. These changes have the potential to de-couple symbiotic associations by altering the ecology of both organisms.

The award is for nearly $30,000 over three terms, candidacy tuition and registration fees for fall and winter, and GradCare health coverage. An award reception was held April 7, 2015.

The Rackham Predoctoral Fellowships are one of the most prestigious awards given to graduate students by the Rackham Graduate School, according to the event program. Those selected for this 12 month fellowship have advanced to candidacy and are anticipating finishing their Ph.D. within six years of beginning their studies. The award takes into consideration professional papers and presentations, publications, honors, as well as academic standing. An important part of this application process is the submission of the dissertation abstract, a dissertation statement, and letters of recommendation from faculty.

Additionally, Gould published a paper in the March 2015 journal, Coral Reefs with her advisor, Dunlap, and Saki Harii of the Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa, Japan.

“This study examined the olfactory preferences of the symbiotically luminous coral reef fish, S. tubifer,” Gould explained. “Chemical cues are known to play an important role in navigation for fishes and I wanted to determine which cues S. tubifer might use to help navigate back to a home reef or urchin. I used a choice flume to present individual fish with different chemical cues and determined whether the fish exhibited a preference for certain cues in their environment over background reef water. The results suggest that S. tubifer prefers the odor of the same species fish but not that of its host urchin species. Small juveniles also preferred the water from their home reef to that of a foreign reef, suggesting that larvae might also use olfaction to navigate to a settlement (home) site. Surprisingly, the host fish also exhibited a preference for the chemical cue of its luminous bacterial symbiont. This is the first time olfaction has been examined for a bioluminescent symbiosis.”