Adults: Five short, stout, tapered arms extend from a thick body. Knobby spines form geometric patterns. Typically tan to orange-brown, with yellow to dark brown spines and occasional lines. Sometimes grey.
Juveniles: Flatter than adults and more variable in colour and designs...green, grey, yellow, white etc with contrasting mottled patches.
Sand and seagrass from 3-120ft (1-40m). Omnivore,and also a deposit feeder. Oreaster reticulatus feeds on echinoids, holothuroid juveniles, and other invertebrates including polychaete worms, copepods, ostracods, crab larvae and sponge tissue. The seastar piles sediments and everts its large cardiac stomach, which allows it to surround the food. Digestive juices are then excreted to break down the food. Edible sponge species might be chosen in preference to other prey.
The sexes are separate and breeds all year round. Fertilization is external. Sperm and eggs are released when a male and a female seastar are in close proximity. The seastars will reproduce when there are dense aggregations, up to 14 per square meter. Having large numbers of males and females ensures eggs will be fertilized. Oreaster reticulatus lays large and bouyant eggs in water currents. The planktonic larvae will be completely developed but will loose their bouyancy, settle and metamorphose in seagrass beds within 23 days at 23 degrees C. Sexual maturity is reached at a radius of 0.12 m. The last juvenile stage measures 0.06-0.12 m in length.
The lifespan of the cushion seastar depends on food availability. If there is low food availability, the cushion star will re-absorb its own tissue, which leads to a reduction in size.
| Ecological Descriptors
Cushion Sea Star ADULT
Red Cushion Star
West Indian Cushion Star