Fish and Marine life Living coral Snorkeling History Visiting Feedback
Your location: Homepage » Fish and marine life » Sea Urchins





Moray eels

Butterfly fish




A large red fingered slate pencil urchin (ina ula) on the rocks.

Sea Urchins

Sea urchins, called wana by the Hawaiians, are common on the floor and rocks of Hanauma Bay. There are several different types of sea urchins within the Hawaiian waters. Each has its own unique name and characteristics. Some are dangerous but most are not.

There are two species of rock-boring sea urchins called ‘ina. One species varies from bright white to dark pink (‘ina kea are white and the ‘ina ‘ula are red). The ‘ina ‘ele ‘ele are a closely related dark species. They are residents of the upper tide pools of Hanauma bay and make their own holes with their sturdy spines. They spines are not toxic, but are sharp enough to be painful if stepped on.

The hawa ‘e is a purplish-black sea urchin with has short and slender spines. It is a rounded body and is called a “collector” urchin because it holds onto bits of seaweed, gravel and shell. Another collector urchin, the gray hawa ‘e po’o hina collects pebbles. They both reside in the shallow reef areas of the bay. Because of their collections they may appear hidden to snorkelers.

Armored urchins have spines designed for life in special habitats. The shingle sea urchins (ha ‘uke ‘uke) have flattened spines and dome-shaped bodies to protect them from the pounding surf. They inhabit the wave impact zone of Hanauma Bay.

All sea urchins have circular to oval shapes. They have five zones of tube feet and then five zones spines that run from the mouth on the urchin’s underside to the top of the body. The many tube feet are used to attaching them to the sea floor, for moving and sometimes food capture.

Most sea urchins are seen on hard surfaces like rocks and coral reef. They wedge into protection by day and them emerge at night to graze on algae.

Sea Urchin safety

Sea urchins are a minor threat while snorkeling. The most dangerous urchins have thin needle-like spines that are venomous. However, all urchins can injure your feet if you step on them.

Protect yourself while snorkeling by following a simple set of precautions. Wear water shoes or flippers during your snorkeling at Hanauma bay. Do not stand directly on any rocky surface or coral. If you must stand, inspect the area before you place your foot down.

If you do become injured by a venomous sea urchin, a lifeguard on duty can help with first aid. However, with proper precautions while you are snorkeling, you shouldn’t have to worry about sea urchin injuries.