Information from Bob Fenner
The arms/branchlets bear pinnules that convey food via seemingly twitching their tube feet toward and across an elaborate conveyor system. During feeding the arms and pinnules are outstretched and their podia are erect. The papillae along the length of the podia are secreting mucus, plankton becomes trapped in the mucus and the podia tosses it into the ambulacral groove where cilia carries it to the mouth. The mouth in turn leads to a short esophagus then intestine. The intestine makes one or more turn down around the aboral side of the animal then turns around and heads back up to a short rectum and anus. Waste is ejected as mucus balls which drop from the anal cone. The whole of this digestive tract is lined with undulating cilia.
Most species are nocturnal suspension feeders. You will want to have timers to cut off your particulate filter(s) during these feeding bouts. Best done by using timers to switch the filter pump motors off for ten to fifteen minutes.
Food material in the wild includes all manner of phyto- and zooplankton and general detritus. In public aquaria, cultured diets of brine shrimp nauplii, copepods and diatoms have proved effective.
Disease: Infectious, Parasitic
None noted.
Other Biology of Interest:
Though the size of extant forms is a few inches to a couple of feet in dimension, that of some extinct crinoids was very great. One (Extracrinus subangularis had a stalk of nearly 21.5 meter! in length. Yowzah.
By any visit to your friendly neighborhood or national natural history museum you can gain an appreciation for how species-rich and dominant crinoids were in reef communities of the geological past.
Close:
The un-stalked, commercially available Feather Stars are oft brilliantly colored/marked and not impossible to keep. They are for the most part entirely non-obnoxious, being non-predatory, not-tasty, and disease-free; perfect reef tank candidates.
Thought to be extinct prior to dredging studies by the Challenger expeditions of the 1870's, free-living crinoids are difficult but not impossible aquarium specimens. Requisite are selecting healthy individuals, providing subdued lighting and hiding spaces and an accommodating crepuscular to night time feeding routine.