Content area
Full text
About the Authors:
Gary M. King
* E-mail: [email protected]
Affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America
Craig Judd
Affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America
Cheryl R. Kuske
Affiliation: Bioscience Division, MS 888, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
Conor Smith
Affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America
Introduction
The Eastern oyster, Crassostrea virginica, is well known for its commercial value and importance as an “ecosystem engineer” [1]–[3]. Volumes have been written about its biology and ecology, including interactions with bacteria and other microbes. Much of this literature has emphasized diseases [4], [5] and the presence of human pathogens, especially Vibrio parahaemolyticus and V. vulnificus [6]–[9].
Many studies have addressed other aspects of oyster-bacteria interactions. Cristispira has been identified as a symbiont associated with the crystalline style, a molluscan digestive structure [10]. Stappia (now Labrenzia) has been isolated from C. gigas and C. virginica, and in the latter implicated as an antagonist for the etiological agent of Juvenile Oyster Disease [11]. Culture-dependent studies have characterized Vibrio and other genera associated with bulk animals and specific tissues [6]–[8], [12], [13] including identification of “indigenous” bacteria in C. gigas haemolymph [14], [15]. Such studies have also shown that an Eastern Mediterranean oil spill did not affect oyster-associated bacteria [16]. Culture-independent studies have documented patterns of diversity among different populations and tissues, compared hatchery-raised and wild animals, and identified the ε-Proteobacterium, Arcobacter, as a major contributor to the microbial community of the Chilean oyster, Tiostrea chiliensis [17].
Despite the pathogen-associated and fingerprinting studies summarized above, and the potential importance of bacteria for oyster nutrient acquisition, surprisingly little information exists on oyster stomach and gut microbiome diversity. Although pH values of stomach and gut tissues are similar, and particle transit times relatively short (about 1–2 h) during active feeding [18], it is unclear whether characteristic communities exist in the contents of these tissues; it is equally uncertain how microbiomes might vary within a population or across populations. To address these questions, we obtained two sets of triplicate animals, one set each from Hackberry Bay and Lake Caillou in coastal...