Christmas tree worms
Fig. 31: A whole population of christmas tree worms in a stone coral. The colourful spiral feathers are gills that they draw in rapidly when danger or a photographer approaches. — Sea & Sea DX-8000G, Koh Rok, Thailand, December 2007 — EXIF: Caplio GX8; Δt=1/871 s; f=5.8 mm; f/2.5; ISO 200; 2007-12-27 5:26:56