Possibly SPIRORBIS SPP. (Spiral tube feather dusters (spirobids) apprx. 1/4" is size, from tropical seas, lighting is immaterial, feeds on particulate organic material and phytoplankton, may survive on dissoved nutrients. easy to maintain and are harmless. If this is in fact what you have, they are the tiniest of the feather dusters and make their way into virtually all marine aquariums. Tubes are usually spirally coiled about 1 1/3 to 1 1/2 whorls and often first spotted on the walls of the tank. The minuscule crown is generally brilliant red or blaze orange, but tentacles are difficult to see because of their small size. Spirorbids are simultaneous, self fertilizing hermaphrodites. The larval period is short and the adults brood the larvae in their tubes. Juveniles exit the parents tube and crawl a short distance before starting to secrete their own tubes. once the tube is started they remain in place for the rest of their lives. no special care is needed to maintain these harmless animals. Eaten by copperband butterfly fish.
