Relationship of Vibrio Species Infection and Elevated Temperatures to Yellow Blotch/Band Disease in Caribbean Corals
James M. Cervino,1* Raymond L. Hayes,2 Shawn W. Polson,3 Sara C. Polson,3 Thomas J. Goreau,4 Robert J. Martinez,5 and Garriet W. Smith6
University of South Carolina, Columbia,1 Hollings Marine Laboratory, Medical University of South Carolina, Charleston,3 University of South Carolina, Aiken, South Carolina,6 Howard University, Washington, District of Columbia,2 Global Coral Reef Alliance, Cambridge, Massachusetts,4 Georgia Institute of Technology, Atlanta, Georgia5
The bacterial and temperature factors leading to yellow blotch/band disease (YBD), which affects the major reef-building Caribbean corals Montastrea spp., have been investigated. Groups of bacteria isolated from affected corals and inoculated onto healthy corals caused disease signs similar to those of YBD. The 16S rRNA genes from these bacteria were sequenced and found to correspond to four Vibrio spp. Elevating the water temperature notably increased the rate of spread of YBD on inoculated corals and induced greater coral mortality. YBD-infected corals held at elevated water temperatures had 50% lower zooxanthella densities, 80% lower division rates, and a 75% decrease in chlorophyll a and c2 pigments compared with controls. Histological sections indicated that the algal pyrenoid was fragmented into separate segments, along with a reconfiguration and swelling of the zooxanthellae, as well as vacuolization. YBD does not appear to produce the same physiological response formerly observed in corals undergoing temperature-related bleaching. Evidence indicates that YBD affects primarily the symbiotic algae rather than coral tissue.
Applied and Environmental Microbiology, November 2004, p. 6855-6864, Vol. 70, No. 11.