Naked Basket Star

This species is a typical basket star, with arms divided into five sections, with many smaller arms branching off of these sections. The arms can range throughout a variety of lengths both within and among individuals of Astroboa nuda. Shorter arms help the basket stars attach themselves to a substrate, and may also help carry food from the longer arms, which catch prey, to the mouth.

A. nuda have a simple digestive system, consisting of an esophagus connected to a sac-like stomach. They have no anus or intestines. The mouth is found on the underside of the body. The waste product of basket stars comes in the form of ammonia, and is removed from the body through diffusion.

Astroboa nuda are found throughout the tropical seas of the Indo-Pacific, occurring in the Gulf of Aqaba at its northernmost range, down south to Madagascar, Mozambique and South Africa, and eastwards to the seas around Indonesia, the Philippines, the northern coast of Australia, New Caledonia, and Vanuatu.

Like other gorgonocephalids, they are benthic, commonly being found on the seafloor at depths greater than twenty meters, and up to 120 metres (390 ft) down in submarine canyons in Sodwana Bay. Unlike some other species within Ophiuroidea that form aggregations, Astroboa nuda are usually found alone or in groups of two to four.

Astroboa nuda is a filter feeder and usually feeds on plankton, such as the larvae of decapods and copepods, as well as those of fish. Due to their light sensitivity, A. nuda hides in nearby shelters during the day, but branch out at night to feed; a high-powered electric torch may induce a similar retreat to shelter. They feed from approximately two hours after sunset, to about one hour before sunrise. They usually return to the same spot every night, and are active during all seasons of the year. They prefer calm, lightly disturbed waters. If the area is heavily disturbed causing irregular current, they usually remain sheltered behind coral heads, or other sections of the reef.