Echinoderms: Part 8 - Feather Stars (Crinoidea)
Drs. Foster & Smith Educational Staff
Michael Paletta - Guest Author
While sea urchins may be considered the
brutes of the echinoderms, feather stars
are the delicate flowers of the group. They
are delicate not only in terms of
appearance, but also due to the great
deal of difficulty that has plagued
hobbyists that have tried to keep them.
They are the most primitive of the echinoderms, so much so that they only have a single opening that function as their
"mouth" and "anus." This opening is located on the upper portion of their body. This configuration allows them to move the
food, which they capture with their feathery arms, directly to their mouth and to expel waste so that the strong current in
which they thrive in carries it away from their body. These animals have small "feet" called cirri, which they use to attach
themselves to the reef. Once successfully perched in a spot, they expand their arms that act like nets to catch plankton and
other foods as it passes across them on the reef. This behavior makes them appear like flowers or feathers blowing in the
breeze.
The lack of strong surge and adequate food is probably the main reasons why these animals tend to fail in captivity. On the
reef, large quantities of organic particulate matter constantly move across the reef so these animals can readily obtain adequate
nutrition. Replicating these conditions in a closed environment is very difficult since large amounts of food allowed to float in
the aquarium can rapidly cause conditions to deteriorate.
Furthermore, most systems do not have the water movement and surge that these animals seem to require. Evidence that these
animals are not thriving is seen when these animals rapidly drop portions of their arms. In the wild, this is a natural defense
mechanism and the arms rapidly grow back, but in captivity when the arms fall off very rarely do they grow back. Eventually
all of the arms fall off and the animal has no means of capturing food and slowly starves to death. This happens in even the
best systems where food is specifically given to these animals. Until we determine what is lacking for the proper care of these
animals, feather stars should not be kept.
They are one of the most difficult animals to keep with long-term success. Only experienced hobbyists willing to provide for
their demanding needs should attempt keeping them. Even so, success is not guaranteed so most hobbyists should not try to
keep them and they should only rarely be imported.
[Update 11-01-2010]
"While what Mike writes is true for most of these animals and the vast majority of
hobbyists out there, things have changed quite a bit, especially in the last year or two.
There have been significant advances in nutrition, particle size, and even a new variety
of foods available to enthusiasts who have the expertise and knowledge to maintain
dedicated NPS (Non-Photosynthetic) aquariums. The secret with keeping Crinoids on
a long term basis (as well as other more delicate zooplankton and phytoplankton eating
animals) lies in the exact foods being offered, along with frequency of feeding, while
all the while maintaining perfect water chemistry. Although not for everyone, for the
very experienced enthusiast with the skill, knowledge, and time to properly feed these
animals frequently, success can be achieved. We encourage interested aquarists to
Echinoderms: Part 8 - Feather Stars (Crinoidea) - Page 1 of 2
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prohibited under copyright law. Site content, including photography, descriptions, pricing, promotions, and availability are subject to change without
notice. These restrictions are necessary in order to protect not only our copyrighted intellectual property, but also the health of pets, since articles or
images that are altered or edited after download could result in misinformation that may harm companion animals, aquatic life, or native species.
continuing researching this evolving and exciting corner of the hobby."
Kevin Kohen, Director of LiveAquaria.com
Part 8 of 8. Continue reading:
Part 1
Part 2
Part 3
Part 4
Intro
Unique
Chararcteristics
Unique Defense
Chararcteristics
Sea Stars
(Asteroidea)
Part 5
Part 6
Part 7
Part 8
Brittle & Serpent
Starfish (Ophiuroidea)
Sea Cucumbers
(Holothuroidea)
Sea Urchins
(Echinoidea)
Feather Stars
(Crinoidea)
Biography
Michael Paletta is the author of two books, "The Modern Marine Aquarium" and "Ultimate Reefs," and
has acted as a consultant with the National Aquarium in Baltimore and the Pittsburgh Zoo Aquarium.
Echinoderms: Part 8 - Feather Stars (Crinoidea) - Page 2 of 2
Unauthorized use of any images, thumbnails, illustrations, descriptions, article content, or registered trademarks of Foster & Smith, Inc. is strictly
prohibited under copyright law. Site content, including photography, descriptions, pricing, promotions, and availability are subject to change without
notice. These restrictions are necessary in order to protect not only our copyrighted intellectual property, but also the health of pets, since articles or
images that are altered or edited after download could result in misinformation that may harm companion animals, aquatic life, or native species.