Red sea urchin

Biology

The red sea urchin is one of the largest sea urchins, reaching 25 centimetres in diameter. The colour of its long spines, which can be half the size of its shell, varies from red to brown and purple. These structures function as microhabitats as young urchins and small fish avoid predation under their protection. This species is found in large groups near kelp beds.

Conservation

The primary food source of these sea urchins is kelp. That is why red sea urchins are so important for the maintenance of these brown algae’s growth. However, if the number of these sea urchins increase too much, the kelp forests can be in great danger. As it is one of the favourite food sources of the sea otter, this species has been kept under control.

Curiosities

Like other sea urchin species, the red sea urchin has five teeth organized in a structure called Aristotle’s Lantern. This species uses these teeth not only to feed but also to dig holes to hide and rest.