Naked Basket Star

Overview

The Naked Basket Star (Astroboa nuda) is a large, complex echinoderm known for its highly branched, intricate arms. It is a nocturnal species that spends its daylight hours hidden in reef crevices, emerging at night to feed in areas with active water currents.

Distribution & habitat

This species is widely distributed throughout the Indo-Pacific, ranging from the Red Sea to New Caledonia. It typically inhabits reef slopes where it can find rocky or coral outcrops to anchor itself while facing into the current.

Appearance

Astroboa nuda features a central disk with five primary arms that divide repeatedly into a dense, lacy network of smaller, curling tendrils. These arms can reach significant lengths, and when fully extended, the animal forms a large, basket-like shape to capture prey. The coloration is generally cream to whitish.

Biology & behavior

This basket star is highly sensitive to light; even the beam of a flashlight can cause it to rapidly collapse its branches and retreat into a crevice. It is a nocturnal feeder, typically active from shortly after sunset until just before sunrise. Individuals often return to the same specific location on the reef each night.

Feeding

As a filter feeder, it extends its branched arms into the water column to intercept passing plankton, including fish larvae and the larvae of crustaceans like decapods and copepods. The smaller, specialized branches help transport captured food toward the mouth, which is located on the underside of the central disk.