Green Sea Urchin
The green sea urchin (Strongylocentrotus droebachiensis) is a spiny, olive-green urchin of cold northern seas around the globe. It is a keystone grazer: when its numbers surge, it can clear kelp beds and leave rocky 'barrens'.
The green sea urchin (Strongylocentrotus droebachiensis) is a spiny, olive-green urchin of cold northern seas around the globe. It is a keystone grazer: when its numbers surge, it can clear kelp beds and leave rocky "barrens".
🧬 Field Guide Specimen: Open Green Sea Urchin in the CRV Science Field Guide to log the specimen, see its place among the Deuterostomia lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.
Barrens and Kelp Rebound
In the northwestern Atlantic, urchins increased after predatory fish such as cod were fished out and overgrazed kelp in the 1970s and 1980s. A later disease outbreak killed many urchins in Nova Scotia, and kelp beds recovered in some areas. See Giant Kelp.
A Fishery for Roe
Urchin gonads (uni) are sold to the Japanese market. The Maine fishery boomed in the 1990s and then declined as stocks fell.
Developmental Biology
Like its Pacific relative, the green urchin has been used to study fertilization and embryonic development. See Purple Sea Urchin.
Green Sea Urchin at a Glance
| Property | Value |
|---|---|
| Scientific name | Strongylocentrotus droebachiensis |
| Kingdom | Animalia |
| Phylum | Echinodermata |
| Class | Echinoidea |
| Order | Camarodonta |
| Family | Strongylocentrotidae |
| Field Guide group | Deuterostomia: Echinodermata (Sea Stars & Allies) |
| Diagnostic feature (Field Guide) | Round green test covered in short spines; scrapes algae with a five-toothed jaw; can mow down kelp forests. |
| Class | Echinoidea |
| Role | Kelp grazer |
See Also
- Purple Sea Urchin — a Pacific relative
- Sea Otter — a predator of urchins