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.