Extended Data Fig. 1: Stylatula elongata species identification.
From: A widespread metabolic gene cluster family in metazoans
To accurately differentiate between two visually similar southern California sea pen species, Stylatula elongata and Virgularia sp., we examined the presence or absence of sclerites at the base of the polyp leaves. Sclerites are microscopic carbonate structures that provide structural support and serve as important taxonomic markers in octocorals. We imaged these sclerites at 10x magnification to assess their morphology and distribution. The observed sclerites, measuring approximately 0.5–1.5 mm in length, confirmed the identification of the specimen as Stylatula elongata, as this species is known to possess these structures, whereas Virgularia lacks them. The figure illustrates the presence of the sclerites in our sample tissue, providing critical diagnostic evidence for species determination.
