It is mostly found at depths of between 50 and 180 m (160 and 590 ft), but around the coast of New Zealand it occurs in shallow waters, in association with the black coral Antipathella fiordensis.

[2] Astrobrachion constrictum has a central disc growing to a maximum diameter of 25 mm (1 in),[3] and five slender arms which may reach a length of 50 cm (20 in).

However, in the Fiordland in the south-western part of the South Island of New Zealand, unique conditions allow them and their black coral hosts to live in shallower waters where they are within the range of divers and more readily studied.

[4] The basket stars feed at night, uncoiling their arms from the coral and catching organic particles floating past.

They also brush their arms against the coral surface and are probably feeding on detritus and any epizoic organisms that settle there.