These Porites rocks are absolutely loaded with Christmas Tree Worms. These colorful little feather dusters can grow radioles to around 1.5" and feed on mostly phytoplankton. They have a trap door called an operculum and can quickly retract inside their tubes to protect themselves when threatened.
Christmas tree worm rocks are somewhat rare to be seen in the hobby. We got lucky and scored some baseball sized rocks loaded with worms. They are mostly blue feathered worms on these rocks and the Porites coral is purple and has nice green accents developing.
74-78° F, dKH 8-12, pH 8.0-8.4, sg 1.023-1.026