Morning Sun Star, Solaster dawsoni

The morning sun star (Solaster dawsoni) is a species of starfish that is classified within the Solasteridae family. It can be found in northern areas of the Pacific Ocean with a range that extends from the coasts of China, Japan, and Siberia to the coasts of California in the United States. It prefers a habitat in rocky areas at depths of up to 1,380 feet. This species has two subspecies known as Solaster dawsoni dawsoni and Solaster dawsoni arcticus. It has a wide body with eight to thirteen long arms, although individuals with eleven or twelve arms are more common, that often curl up at the tips. It is typically grey, light brown, red, or orange in color with pale spots occurring on some individuals.

Like other species of starfish, the morning sun star is a predator, but this species mainly consumes other species of starfish, which move away as quickly as possible if one is detected. Common prey items vary depending upon the area of its range but include leather stars, which move slowly, and rainbow stars and velcro stars, which move quick enough to defend against the morning sun star. Defense mechanisms include using pedicellariae to stab the attacker or using autonomy to detach an arm and escape. Although this species prefers to consume other sea stars, it is known to feed on sea cucumbers and other morning sun stars. The breeding season of this species occurs between the months of March and June. Both males and females release their gametes at the same time, and once eggs are fertilized, they float with the zooplankton until large enough to sink to the sea floor and develop into young starfish.

Image Caption: The sun star Solaster dawsoni attacking the spiny red sea star Hippasteria spinosa. Washington, Olympic Coast NMS. Credit: NOAA Photo Library/Wikipedia (CC BY 2.0)