From FrugalReef

This article refers primarily to Aspidochirotiacea sea cucumbers. These cucumbers feed by consuming sand. For more information on filter feeding sea cucumbers, please see Sea Apple.

• Disposition: Non-Aggresive
• Hardiness: Very hardy if not overstocked and food is available.
• Reef Safe: Yes
• Max Size: 1 inch to over 1 meter depending on species

[edit] Common Types Available

Aspidochirotiacea sea cucumbers, Dendrochirotacea cucumbers (or Sea Apples) and apodacea (or Medusa Worms) cucumbers. Aspidochirotiacea sea cucumbers are deposit feeding. They use their feet to pick up pieces of sand and consume it. Dendrochirotacea cucumbers are filter feeders. They have very large feathery feeding tentacles and will use their feet to attach themselves in areas of high flow to extend their tentacles in. Apodacea (or medusa worms) are cucumbers without feet and usually feed like Aspidochirotiacea using their mouth tentacles.

[edit] Reef Safety

Aspidochirotiacea Sea cucumbers (Deposit Feeding) are beneficial non-aggressive reef animals that will consume detritus and algae from the substrate of your aquarium and keep your sand clean.

However, if a sea cucumber becomes badly injured it may release toxic compounds. Deposit feeding cucumbers are usually much less toxic than filter feeding cucumbers, but care still needs to be taken to make sure they can't get sucked into pumps or overflows. Additional measures may need to be taken if you intend to keep one of the more toxic types such as sea apples. See Sea Apple for more information on sea cucumber toxicity.

If a sea cucumber does die or become injured, remove it immediately and do a water change. This will probably be sufficient, but you may want to add some activated carbon to the filter, and protein skimmer will also help.

[edit] Feeding

Aspidochirotiacea sea cucumbers feed by ingesting sand and detritus from the aquarium floor. They digest all the bacteria, microalgae and diatoms in the sand and expel the cleaned sand back into the aquarium. To prevent starvation, do not stock more than 3 inches of cucumber per 20 gallons. Sea cucumbers can go months without feeding before starting to show outward signs, and can even digest their own flesh. If you notice your cucumber is getting smaller instead of larger, it is starving. Also, particle size in the substrate is important. Fine sand is preferred. If the particles of substrate are too large for your sea cucumber to consume it will starve. Do not vacuum the substrate if you have a sea cucumber, and do not add one right away to a new tank.