Species identity rather than colony size partitions shape variation in six Caribbean octocorals

Species identity, not colony height, partitions variation in colony shape among six sympatric Caribbean octocorals from St John, US Virgin Islands, with 67.9% of form variation on one PCA axis.

• Why it matters: As scleractinian cover declines, arborescent octocorals dominate reef structure, yet it is unclear whether canopy geometry is driven by species-specific architecture or by size-related allometry.
• What they did: Scaled in situ images were used to model 2D colony form as stacked bands, then PCA on relative band areas tested effects of species identity and colony height.
• The result: Species identity explained 42% of total variation in relative form, while colony height explained 2% with no detectable effect on PCA axes; branch outline proportion increased from 41% at 20 cm to 52% at 100 cm.

AI summary of the abstract · may contain errors · not medical advice · read the paper.