Roller, cushion and knobbed starfish

Roller, cushion and knobbed starfish
	Choriaster granulatus
Systematics
Trunk :	Echinoderms (Echinodermata)
Sub-stem :	Eleutherozoa (Eleutherozoa)
Class :	Starfish (asteroidea)
Order :	Valve stars (Valvatida)
Subordination :	Granulosina
Family :	Roller, cushion and knobbed starfish
Scientific name
	Oreasteridae
	Fisher , 1911

The family of the roller, pillow, and knobbed starfish (Oreasteridae) contains large, heavily armored and voluminous forms that have a reticulate skeleton. They are often clearly patterned with strong, brightly colored spikes and warts.

The approximately 20 genera live mainly in the Indo-Pacific . Only two species of the genus Oreaster live in the Atlantic .

Many Oreasteridae feed on microorganisms, others are scavengers or food specialists . The pillow starfish of the genus Culcita eat polyps from hard corals . In most species, the stomach is everted when they eat and the food is digested outside the body.

Since they look very decorative even when dead, they are often collected, dried, and then sold to tourists. Many species such as the net pillow star ( Oreaster reticulatus ) from the Caribbean have therefore become very rare.

Systematics

Genus Choriaster
- Starfish roll ( Choriaster granulatus ) (Lütken, 1869)
Genus Culcita
- Large pillow star ( Culcita novaeguineae ) Müller & Troschel, 1842
- Spiked pillow star ( Culcita schmideliana ) (Retzius, 1805)