Common name: Sand Dollar

General information

The Sand Dollar, specifically the Encope emarginata, is a fascinating echinoderm that is popular among marine enthusiasts. Unlike the more active sea stars and sea urchins, sand dollars lead a more sedentary lifestyle, spending much of their time partially buried in sandy substrates. Their unique, flattened bodies are adapted for a life spent on the ocean floor.

The name 'Keyhole Sand Dollar' comes from the distinctive keyhole-shaped holes in their tests (skeletons), which are used for respiration and to help the animal stay submerged in the sand.

Care

In the aquarium, Encope emarginata requires a tank with a deep sand bed to mimic their natural habitat. They are sensitive to water quality and require stable conditions with low nitrate levels. Sand dollars are detritivores, feeding on organic material within the sand. A mature, well-established aquarium with a functioning microfauna community is essential for their diet.

Reproduction

Sand dollars reproduce by releasing eggs and sperm into the water column, a process known as broadcast spawning. In the aquarium, this behavior is rare, and successful breeding is not commonly achieved by hobbyists.

Habitat

Encope emarginata is typically found in warm, shallow waters where they inhabit sandy bottoms. They are often found in groups and can be an indicator of a healthy benthic environment. Their range extends across the Gulf of California and along the western coast of Central America.