Also known as Collector Urchin, Indian Urchin, Sea Hedgehog, White Sea Urchin.
Found hiding during the day, in holes and hollows of coral and rock reefs rich in algae growth, coming out to feed at night. Often covered in algae, debris and pebbles.
They feed on algae and seagrasses.
Length - 13cm
Depth - 0-100m
Widespread Indo-West Pacific
Miner's Urchin Shrimp - Gnathophylloides mineri clings to the 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!! Ref: https://www.sealifebase.se/summary/Pseudoboletia-indiana.html