Starfish · Valvatida · Oreasteridae

Horned Sea Star

Protoreaster nodosus

Not Evaluated

It has not yet been assessed against the IUCN criteria. See full glossary

The chocolate chip sea star, robust and cream to reddish, with a row of dark conical tubercles along each arm. It lives on sandy bottoms and seagrass meadows, where it feeds on detritus, sponges and small invertebrates.

Size

15 cm – 30 cm

Diet

Omnivore

Combines animal and plant food depending on availability.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Unknown

OceanOmnivore Solitary Ocean Echinoderm

61countries 35parks

Fun facts

It is one of the most heavily collected sea stars in the world, sold dried as a tourist souvenir, a pressure that has wiped out whole populations in South-East Asia.
Its tubercles often house small commensal shrimps and worms that live nowhere else.
Like all sea stars, it moves on hundreds of hydraulic tube feet driven by a system of pressurised water canals.
Its dark conical tubercles on a pale ground give it the name chocolate chip sea star and make it unmistakable.
It is collected in bulk for the souvenir and ornament trade: they are dried and sold, and that pressure has cut its populations in several areas.
It hosts commensals on its own body, among them shrimps and scale worms that live between its tubercles.
Like all starfish, it digests outside its body: it everts its stomach over prey or sediment and absorbs the organic matter.