Morning Sun Star

The morning sun star has a wide disc and 8 to 13 (usually 11 or 12) long, tapering arms, often with turned-up tips. The upper or aboral surface is smooth, and its colour is usually red, orange, grey, or pale brown, sometimes with paler patches. It grows to a width of about 40 cm (16 in).

The morning sun star occurs in the northern Pacific Ocean at depths to about 420 m (1,380 ft). Its range extends from Japan, China, and Siberia to the coasts of North America as far south as California. It is often found in rocky habitats, but can also inhabit other types of seabed.

The morning sun star is a predator, feeding mostly on other starfish. It is feared by other stars which move away as fast as they can if touched by a morning sun star. In British Columbia, about half of its diet consists of leather stars (Dermasterias imbricata), which move too slowly to evade it. Other sea stars such as the velcro star (Stylasterias forreri) and the rainbow star (Orthasterias koehleri) fight back at their attacker. They have numerous tiny pincer-like organs called pedicellariae and coil their arms around the morning sun star, nipping it with these. It recoils and its prey often manages to escape. Another sometimes successful defence strategy is used by the slime star (Pteraster tesselatus) which inflates its aboral surface making it difficult for the attacker to get a grip on it and at the same time exudes copious amounts of noxious mucus.