Purple Spined Sea Urchin

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Project Description

Purple Spined Sea Urchin

Arbacia punctulata

Range/Geographical Distribution: Found from Cape Cod to the West Indies.

Habitat: Rocky or shell substrates.

Description: A small, round urchin with a tan/gray body and white spines tipped with purple.

Size: The test (body) can reach two inches in width.

Food: Grazes on algae and other organisms found on hard surfaces.

Breeding: Separate sexes; males and females release sperm and eggs into the water.  The fertilized eggs settle and hatch into larvae.

Predators: Long spines protect urchins from most predators.

Conservation Status:  No legal status.

Interesting Facts:  Sea urchins are radially symmetrical and feed with a special structure at the bottom of their body called an Aristotle’s lantern.  This “lantern” consists of five plates that move like a beak in order to scrape the algae off of rocks and the plates can grow back after too much wear.

On the Coast:  Live sea urchins are rarely seen but their test (body) often washes up onto Georgia’s beaches after they die.

Project Details


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