Common name: Sand Sifting Starfish

General information

The Sand Sifting Starfish, Astropecten jonstoni, is a species of sea star found in the Mediterranean Sea and parts of the Atlantic Ocean. It is known for its ability to burrow into the sand, which is a behavior that can be both beneficial and problematic in a reef aquarium. These starfish are efficient at cleaning the sand bed by consuming detritus, uneaten food, and dead or dying organisms.

Care

In the aquarium, Astropecten jonstoni requires a deep sand bed to thrive, as it likes to bury itself. It's important to have a sufficient area of sand and not too many rocks or corals on the bottom, as this could limit the starfish's ability to move and feed. They are sensitive to rapid changes in water parameters, so stability is key. They should be kept in a tank with stable salinity, temperature, and pH, and they should not be exposed to copper-based medications.

Reproduction

Reproduction in Astropecten jonstoni is not commonly observed in the home aquarium. In the wild, they reproduce by releasing gametes into the water column, where fertilization occurs externally. The larvae are planktonic before settling to the bottom and metamorphosing into juvenile starfish.

Symbiosis

While Astropecten jonstoni does not have notable symbiotic relationships like clownfish with anemones, its role in the sand bed can be seen as a form of mutualism with the aquarium system. By sifting through the sand, it helps to aerate and clean the substrate, which can benefit other inhabitants by reducing the buildup of harmful compounds.

Habitat

The natural habitat of Astropecten jonstoni includes sandy bottoms and seagrass beds where it can easily burrow and find food. They are typically found at depths ranging from shallow waters to about 100 meters.