Also known as Setosum Spined Urchin, Diadem Urchin, Diadem Sea Urchin, Long-spined Sea Urchin, Black Longspine Urchin, Long-spined Black Sea Urchin, Pacific Long-spined Black Sea Urchin, Hatpin Urchin and Needle-spined Urchin.
Found in large groups moving across the sand and rubble in bays and lagoons.
Identified by the light coloured ring around the anal cone at the centre.
They feed on invertebrates, sponges and even dead fish.
Length - 20cm
Depth - 0-20m
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!!