Common name: Green Brittle Star

General information

The Green Brittle Star, Ophiarachna incrassata, is a species of brittle star often found in the home aquarium. This nocturnal invertebrate is known for its long, slender arms which it uses for locomotion and capturing food. Its coloration ranges from green to brown, providing excellent camouflage against the substrate and rocks.

Brittle stars are fascinating creatures, with their central disc containing all their vital organs and their arms being capable of regeneration if damaged. They are opportunistic feeders, preying on small fish and invertebrates, as well as scavenging for detritus and uneaten food.

Care

Green Brittle Stars require an established aquarium with plenty of live rock and a sandy substrate to thrive. They are sensitive to changes in water quality, so maintaining stable water parameters is crucial. They are generally hardy and can adapt to a variety of conditions, but they do best in a well-oxygenated environment.

Feeding should be varied, including meaty foods such as shrimp, squid, and fish, as well as some vegetable matter. It's important to ensure that food reaches the bottom of the tank where the brittle star can access it.

Reproduction

Reproduction in Ophiarachna incrassata is not commonly observed in the home aquarium. In the wild, they reproduce by releasing eggs and sperm into the water column, where fertilization occurs externally. The larvae then go through several planktonic stages before settling to the bottom and developing into adults.

Symbiosis

While not known for any specific symbiotic relationships, brittle stars often share their habitat with other reef organisms and can be part of a diverse and balanced reef ecosystem.

Habitat

Green Brittle Stars are typically found in reef environments, often hiding during the day and becoming more active at night. They are widespread in the Indo-Pacific region, inhabiting various depths and often found under rocks or within the reef structure.