Quote from Fenner
"Although there are many beautiful and tempting choices available today, many have specific needs that cannot be supplied by most hobbyists. It makes researching "before" purchasing, of vital importance. This group, in particular, is a very poor choice because of its overwhelmingly dismal rate of survival. Most starve to death within a relatively short period of time. Well, these are among the most difficult animals that you can keep in aquaria. They require large quantities of very fine plankton, which are pretty difficult to come by in aquaria. In the long run, they are best avoided..."