The Bristle Star (Ophiomastix janualis) is a tropical marine (saltwater) echinoderm, related to the starfish. It is also called a Serpent (Snake) Star. It is not a fish. It is an invertebrate (animal with no backbone) and an ophiuroid.

The Bristle Star has five long, slender whip-like arms radiating symmetrically from a central coin-shaped or disc-shaped body. The body contains its mouth and internal organs. Its mouth, on the underside of the body, has five toothed jaws. Its mouth is both the entrance to its internal organs and the exit to release waste.

Brittle Star

It measures about 3 centimetrs (1 inch) without its arms. Its arms measure up to 60 centimetres (24 inches) in length.

The Bristle Star is native to the Indo-West Pacific Ocean. It prefers deep tropical coral reefs and lagoons, with a sandy bottom. It lives in holes and crevices in coral and rocks.

It can crawl across the sea floor using its flexible arms for locomotion. It can regenerate an arm if it is damaged or discarded.

It is a detritivore, and a scavenger, eating small organic dead matter.

Females lay eggs. The eggs develop into juveniles, which are free-swimming larvae. The larvae metamorphose into tiny brittle stars which sink to the bottom of the ocean where they grow into adult form.

The Brittle Star may live up to 5 years.

Brittle Star

Brittle Star

Photographer: Martina Nicolls

Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM