PacSci Perspectives


Sea Star Crossed Lovers: How Do Sea Stars Mate?

Feb 13, 2019

Just in time for Valentine’s Day, there is romance in the air…er, in the water at Pacific Science Center. Our Living Exhibits staff noticed something in our Salt Water Tide Pool recently, which is an event we seldom see among the inhabitants of the Tide Pool, our Ochre sea stars were spawning.

Ochre sea stars do not mate with one partner for life, rather they reproduce sexually and asexually in groups, and according to the University of Puget Sound, the Pisaster ochraceus, or more commonly known as the Ochre sea star, can start breeding at the age of five and typically spawn during the summer—so this is definitely a bit early for our sea stars—but not unheard of.

It’s a bit tough to distinguish male sea stars from female sea stars because externally they look the same to us. Both female and male sea stars release their reproductive cells into the water, where the eggs are then fertilized by the sperm. Ochre sea stars, are also considered “broadcast spawners” which means that once the eggs are fertilized, baby sea stars, or “larva” typically float around in the water and eat zooplankton for a few weeks before they metamorphosis into the tiny versions of sea stars that we know and love.

Speaking of reproduction, follow the PacSci Facebook page for updates on our upcoming exhibit, Our plentiful planet, opening to the public in March and focusing on the topic of reproduction.