. . . aggiungo che ho letto di chi dice che valori di calcio non al top sono motivo del "disfacimento" dell'animale, che e' per lo piu' a struttura calcarea. Inoltre ho trovato un sito di allevatori di coralli e altri invertebrati (tra cui crinoidi) su cui si riporta:
We are able to keep feather stars in an aquarium, but it is difficult to rear them to larger sizes. The problem is the lack of food. As mentioned above, they feed on plankton and organic particles in their natural environment. Also, they seem to feed for many hours a day. In the aquarium, providing them with enough food would cause water pollution, so feeding them sufficiently is not easy. Providing them with live feeds such as brine shrimp (Artemia salina) would be a solution. We try to feed them ground copepods, wheel animalcules (rotifers such as Brachionus plicatilis), diatoms and brine shrimp as much as possible.
http://www.coralscience.org/main/art.../feather-stars