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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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In partial fulfillment of the requirements for the degree of
Master of Science in Biology
in the
School of Biological Sciences
Mary McWhirt
Will defend her thesis
“Microbiome Variation in Wild vs. Captive Eagle Rays (Aetobatus narinari)”
Thursday, July 18, 2019
1:00 PM
Ford ES&T L1118
Thesis Advisor:
Dr. Frank J Stewart
School of Biological Sciences
Georgia Institute of Technology
Committee Members:
Dr. Lisa Hoopes
Director of Research, Conservation and Nutrition
Georgia Aquarium
Dr. Brian Hammer
School of Biological Sciences
Georgia Institute of Technology
Abstract:
The microbial communities (microbiomes) associated with elasmobranchs are currently not well-understood. The spotted eagle ray (Aetobatus narinari) is a slow-maturing ray that is globally distributed in tropical and warm-temperate waters, and is listed as near-threatened by the IUCN Red List. To test how the environment shapes the spotted eagle ray microbiome, we used 16S rRNA Illumina sequencing to compare the microbiomes of the dorsal skin, gill, and cloaca from a ray population near Mote Marine Lab (Sarasota, FL) to those from a captive population in the Ocean Voyager exhibit at Georgia Aquarium, while also analyzing water column microbiomes from both environments. Cloaca microbiomes of both populations had the lowest alpha diversity and highest beta diversity, potentially indicating the presence of transient microbes associated with changes in diet between the environments. The composition of the gill and skin microbiomes differed between captive and wild populations and are similar to, but distinct from, the water column communities while cloaca microbiomes are more dispersed from the water. This pattern is consistent with that seen in teleost fishes and marine mammals. These results indicate a dual role for body niche and environmental conditions in shaping ray microbiomes and identify key taxa that may be important to the health of the rays.
