# What Do Sea Urchins Eat?

> What sea urchins eat: Mostly herbivore (algae and kelp), foraging style, and seasonal shifts in Reefs, rocky seabeds, and kelp forests worldwide.

- **Species:** Sea Urchin (*Echinoidea*)
- **Conservation status:** Least Concern
- **Diet:** Mostly herbivore (algae and kelp)
- **Habitat:** Reefs, rocky seabeds, and kelp forests worldwide
- **Lifespan:** 10–30 years (some far longer)
- **Top speed:** Very slow; creeps on tube feet and spines
- **Canonical HTML:** https://globalanimalguide.org/animals/sea-urchin/what-do-sea-urchin-eat/
- **Parent profile:** https://globalanimalguide.org/animals/sea-urchin/
- **Last reviewed:** 2026-07-16

## Quick answer

Sea urchins are round, spiny marine invertebrates related to starfish, with a hard shell called a test covered in movable spines. They graze on algae across reefs and rocky seabeds worldwide, using a five-toothed mouth on their underside known as Aristotle's lantern. Most live around 10 to 30 years, and some species are very long-lived.

## Who should skip this page

Skip this if you need a captive feeding plan from a veterinarian. This page is wild diet, not a pet-care sheet.

## Spines and shell

A sea urchin's body is a rounded shell called a test, built from fused plates and covered in movable spines. The spines provide defense against predators, help with movement, and in some species carry mild venom. Between the spines, tiny tube feet extend to grip surfaces and gather food.

## Help protect the Sea Urchin

Even familiar animals lose ground as wild habitat keeps shrinking worldwide.

[Donate to wildlife protection](https://worldanimalrescuenetwork.org/donate/)

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Source: Global Animal Guide (https://globalanimalguide.org/animals/sea-urchin/what-do-sea-urchin-eat/). Licensed CC BY-NC 4.0 — free for non-commercial reuse with attribution.