Echinodermata · echinoderms
Red sea urchin
Mesocentrotus franciscanus
Strongylocentrotidae · temperate urchinsIUCN: Not evaluated
A large Pacific urchin whose roe is sold as uni.
Fun factIt may live for more than 100 years.
- Waters
- North Pacific, Eastern Pacific
- Depth zone
- Coastal shallows & estuaries
- Diet
- Kelp
- Size
- Test up to 18 cm
Classification
Echinodermata › Echinoidea › Strongylocentrotidae
- Kingdom Animalia animals
- Many-celled organisms that eat other living things for energy (heterotrophs)
- Cells have no cell walls
- Most can move at some stage of life
- Clade Bilateria bilateral animals
- Body has a left and right side that mirror each other (bilateral symmetry)
- Head end with concentrated nerves; three tissue layers
- Includes about 99% of all living animal species
- Clade Deuterostomia deuterostomes
- In the embryo, the first opening becomes the anus and the mouth forms second
- Includes echinoderms and chordates
- Phylum Echinodermata echinoderms
- Adults usually have five-part radial symmetry
- Water-vascular system powers tiny tube feet
- Skeleton of limestone plates (ossicles) in the skin
- Class Echinoidea sea urchins & sand dollars
- Sea urchins and sand dollars: rigid, rounded shell (test) of fused plates
- Covered in movable spines
- Jaw apparatus called Aristotle's lantern
- Family Strongylocentrotidae temperate urchins
- Cold-water urchins with short spines
- Major grazers of kelp
- Genus Mesocentrotus
- Species in the same genus are very close relatives and often look alike.
- Species Mesocentrotus franciscanus Red sea urchin
Closest relatives in the guide
- Green sea urchin Strongylocentrotus droebachiensis same family
- Common sand dollar Echinarachnius parma same class
- Long-spined sea urchin Diadema antillarum same class