Common name: black brittle star

General information

The Variable Brittle Star, Ophiomastix variabilis, is a colorful and active echinoderm that is often sought after by reef aquarium enthusiasts for its unique appearance and behavior. This species is known for its long, slender arms which are banded with contrasting colors, typically orange and black or white. The central disc may also exhibit vibrant hues, adding to its striking visual appeal.

In the wild, Ophiomastix variabilis is found in a variety of reef environments, often hiding during the day and becoming more active at night. They are scavengers by nature, feeding on detritus and small organisms, which makes them beneficial for the natural maintenance of a reef aquarium.

Care

Caring for a Variable Brittle Star requires a well-established aquarium with plenty of live rock and a sandy substrate to provide hiding places and foraging grounds. They are generally hardy and can adapt to a range of conditions, but they do best in a stable environment with good water quality.

Brittle stars are sensitive to sudden changes in water parameters, so acclimation should be done carefully. They are not aggressive and can coexist with a wide variety of tank mates, but their long arms can be tempting for nipping fish.

Reproduction

Reproduction in Ophiomastix variabilis occurs through both sexual and asexual means. In the aquarium, they may reproduce by releasing gametes into the water column, where fertilization occurs externally. Hobbyists may occasionally observe tiny brittle stars appearing in their tanks, indicating successful reproduction.

Symbiosis

While Ophiomastix variabilis does not have any specific symbiotic relationships akin to clownfish and anemones, they do play a role in the cleanup crew of a reef tank, helping to maintain a healthy and balanced ecosystem by consuming organic waste.

Habitat

Variable Brittle Stars are typically found in the Indo-Pacific region, from the Red Sea to the Western Pacific. They inhabit coral reefs and rocky substrates, often at depths where light is sufficient for the growth of benthic algae and other potential food sources.