Study Reveals Species-Specific Microbial Changes in Corals with Stony Coral Tissue Loss Disease
A new preprint study examined how microbial communities change within individual coral colonies infected with Stony Coral Tissue Loss Disease (SCTLD), comparing apparently healthy tissue to diseased tissue across three species. Researchers found significant microbial community shifts in two highly susceptible species but not in a moderately susceptible one, with bacterial profiles in diseased tissue being species-specific. The findings suggest that within-colony microbial responses mirror the broader pattern of species-level susceptibility to SCTLD, offering new clues about disease dynamics in the Mexican Caribbean.
Researchers studying Stony Coral Tissue Loss Disease (SCTLD) — a rapidly progressing, high-mortality coral pathology affecting nearly 30 species — analyzed microbial community changes within individual infected colonies in the Mexican Caribbean. Using 16S rRNA Illumina sequencing, the team compared apparently healthy tissue and SCTLD-affected tissue in three species spanning a susceptibility gradient: the highly susceptible Dendrogyra cylindrus (n=11) and Pseudodiploria strigosa (n=6), and the moderately susceptible Orbicella faveolata (n=8). Significant differences in microbial community structure between healthy and diseased tissue were detected in the two highly susceptible species (p=0.01 for both), but not in the moderately susceptible species (p=0.28). While bacterial profiles in SCTLD tissue were species-specific, apparently healthy tissue across all three species shared common microbial groups including Pirellulales, NB1-J, and SAR324. The study concludes that within-colony microbial responses to SCTLD parallel the known susceptibility hierarchy among coral species, advancing understanding of how this destructive disease progresses at the microbial level.
What's missing
As a preprint, this study has not yet undergone peer review. The study is limited to the Mexican Caribbean, and it is unclear whether these microbial patterns generalize to SCTLD outbreaks elsewhere (e.g., Florida). The cross-sectional design cannot establish whether observed microbial shifts are a cause or consequence of tissue loss. Sample sizes, particularly for Pseudodiploria strigosa (n=6), are small. The study does not address potential environmental confounders such as water temperature or local nutrient levels that may influence microbial community composition.
What different sources said
- bioRxivCenter
Within-colony microbial response of three species with different susceptibility to Stony Coral Tissue Loss Disease
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