Also known as Black Longspine Urchin, Diadem Sea Urchin, Diadem Urchin, Hatpin Sea Urchin, Hatpin Urchin, Long-spined Black Sea Urchin, Long-spined Sea Urchin, Needle-spined Urchin, Pacific Long-spined Black Sea Urchin, Porcupine Sea Urchin, Setosum Spined Urchin.
Found singly or in large groups moving across rubble, sand, shingle and seagrass beds in bays and lagoons.
They feed nocturnally on algae.
Length - 20cm
Depth - 0-70m
Widespread Mediterranean, Indo-Pacific
Amongst their spines these sea urchins may have Banggai Cardinalfish - Pterapogon kauderni
Tubed Cardinalfish - Siphamia tubifer
These large sea urchin with long and mobile spines can often be found with fish swimming in between their spines for protection.
Sea Urchins use tubed feet to get around, often in large impenetrable masses for protection.
Sometimes they hitch a lift on the back of crabs.
They have well developed jaws for grinding their prey.
Their anus is on top in most sea urchins, except the heart urchins where it is at the rear.
Predators of sea urchins are triggerfish and large wrasses, who nibble away at their spines before turning them over to eat the fleshy undersides.
Sea Urchins are highly venomous and can piece through a wet-suit.
Some are sensitive to light and have the ability to shoot venom loaded spines at a short distance.
To be avoided!!