Mesocentrotus nudus is a cold-water sea urchin from the northwestern Pacific, fished in Japan and Korea for its edible roe (uni). It doesn't live in US waters; its relative the red sea urchin (Mesocentrotus franciscanus) lives along the Pacific coast.
Appearance
- Appearance
- The shell is about 2.4–2.8 in (6–7 cm) across, with spines about 0.8–1.2 in (2–3 cm) long in dark green, dark purple, or dark brown.
Where it lives
- Typical habitats
- Rocky shores
- Kelp beds
- Rocky reefs
- Range
- Northern Japan, the Korean Peninsula, and the coast of northern China. It is not found in the wild in the US.
- Preferred conditions
- A cold-water species that dies when the water gets above about 79–86°F (26–30°C). It lives from the down to roughly 590 ft (180 m).
Behavior
- Diet
- Mainly seaweed, plus drifting bits of dead plants and animals.
Life cycle
- Reproduction
- Larvae drift in the water for one to two months before settling on the bottom. With enough food, urchins start spawning in their second year.
- Lifespan
- About 14–15 years.
Name and classification
- About the name
- It used to be called Strongylocentrotus nudus and was later moved to the genus Mesocentrotus.
Conservation
- IUCN Red List
- NENot EvaluatedNot yet assessed
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