Skin Microbiome of the Round Stingray, Urobatis halleri, in Southern California

Microbiomes, or all of the microorganisms associated with an organism, provide insight into the health of an organism. Rays are part of the class Chondrichthyes and have several features that may affect the structure of the skin microbiome, including mucus production and benthic lifestyles. Here we describe the skin microbiome composition of the round stingray, Urobatis halleri using shotgun metagenomics. The skin microbiome of fifteen rays was collected from five locations including Long Beach, San Onofre, Oceanside, San Diego Bay (2019), and Mission Bay (2017) in California. To date five metagenomes collected in 2017 have been sequenced on Illumina and annotated using Focus and Superfocus, two kmer based programs. These preliminary results show the skin microbiome of Urobatis halleri is significantly different from the surrounding water column. At the Class level Clorobia and Planctomycetia are more abundant on the skin of rays than in the water column. The functional pathways that are overrepresented in rays include resistance to antibiotics and toxic compounds. In the future, the microbiome from rays will be compared to the microbiomes of sharks and teleost fish. While sharks and rays are related, sharks are covered in dermal denticles with minimal mucus, whereas stingrays have a layer of mucus on their skin, which is a trait more similar to teleost fish. Therefore, we will analyze whether the microbiomes of the two phylogenetically related groups (sharks and rays) is more similar than the two unrelated groups, rays and fish that have a similar trait (skin covered with mucus).