Echinaster callosus belongs to the Family Echinasteridae. It has five long arms that 翹起 at the tips. The arm to disk ratio (R/r) is 13cm/12cm. The calcareous plates are in reticular arrangement. There is clustering of skin gills. Skin gill clusters are located between the calcareous plates. The skin gill areas on the dorsal surface of the arms are larger. At the junction of the calcareous plates are a large vertical spine and a madreporite. On dried specimens there is obvious bulging. Above are a large number of radiating grooves. The anus is located in the center of the disc and is surrounded by 5-7 vertical spines. The 1st, 2nd, and 3rd 溝棘form a line perpendicular to the arm. The 1st 溝棘 is short and small. At the base of the arm, the 3rd 溝棘 has 3-4 branches at the end. The 4th 溝棘 (also called 側溝棘) is thick and large and there are often 5-8 branches rising up from the end. On dried specimens of Echinaster callous, there are two distinct rows of tube feet. The disc and spines are wrapped in thick skin. When soaked in formalin solution, the dried specimens appear purplish red. This sea star inhabits shallow water coral reefs at depths of about 6 meters. It mainly feeds on invertebrates attached to the rocks.

The specimens of Echinaster callosus in the collection of the National Museum of Natural Science were all obtained from Green Island. However, their numbers are few. The major distribution range of this species is from the West Indies to East Africa and Madagascar, the Red Sea, Sri Lanka, the Bay of Bengal, eastern India, the Philippines, southern Japan, southern China and the islands of the South Pacific.