DAO 69:111-118 (2006)  -  doi:10.3354/dao069111

Contribution to the DAO Special 'Current Advances in Coral Reef Disease Research'

A single cyanobacterial ribotype is associated with both red and black bands on diseased corals from Palau

Meir Sussman1,2,*, David G. Bourne2, Bette L. Willis1

1James Cook University, School of Marine Biology and Aquaculture, Townsville 4811, Queensland, Australia
2Australian Institute of Marine Science, PMB 3, Townsville MC, Townsville 4810, Queensland, Australia

ABSTRACT: Filamentous cyanobacteria forming red and black bands (black band disease, BBD) on 3 scleractinian corals from Palau were molecularly identified as belonging to a single ribotype. Red cyanobacterial mats sampled from infections on Pachyseris speciosa and a massive Porites sp. yielded red strains RMS1 and RMS2 respectively; the black cyanobacterial mat sampled from an infection on Montipora sp. yielded black strain BMS1. Following trials of a range of specialized media and culture conditions, 2 media, Grund and ASN-III, were identified as the best for successful isolation and culturing. Cultured cyanobacteria were examined under a light microscope to establish purity, color and morphological appearance. DNA extraction and partial sequencing of the 16S rDNA gene of both red and black cyanobacterial isolates demonstrated 100% sequence identity. These isolated strains were also found to have 99% sequence identity with an uncultured cyanobacterial strain previously identified by molecular techniques as belonging to a cyanobacterial ribotype associated with BBD-infected corals in the Caribbean. This is the first report of the successful isolation and culture of cyanobacterial strains derived from both red bands and BBD. Based on these findings, it is suggested that the classification of these 2 syndromes as separate coral diseases be postponed until further evidence is collected.

KEY WORDS: Coral disease · Black band disease · BBD · Red bands · Red band disease · RBD · Cyanobacterial pigmentation

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