Purple Sea Urchin: Strongylocentrotus purpuratus

An Abundant Kelp Forest Herbivore 

Along the western coastline of North America a cold-water current flows down the coast.  The water is nutrient rich and supports large forests of kelp and other algae.  These forests provide food and habitat for a great number of other animals.  One of the herbivorous predators of these kelp is the Californian Purple Sea Urchin (Stronglyocentrotus purpuratus).  When outbreaks of sea urchins occur, it can be a disaster for the kelp beds.  The number of urchins is controlled by otters, sea stars and the amount of food in the area.  

Where do California Purple Sea Urchins Live?

These sea urchins are found along the west coast of North America from Punta Banda Mexico to British Columbia, Canada.  It is one of the dominent organisms in the kelp forest community.

How large to Purple Sea Urchins Grow?

Most of these urchins will grow to a diameter of 4 inches.  They can live for a long time too - around 70 years old.

Roles in Biomedical Research 

The California Purple Sea Urchin has been chosen as an ideal species for study in genetics.  It is one of the most abundant urchins on the west coast so it is readily available for study.  It is also a deuterostome, a term used to describe the development of the zygote.  Because humans are also deuterostomes, these invertebrates provide great research subjects in developmental biology.  In fact, we share about 7,700 genes with these urchins and this study of their genetics can shed light on our own.