The Cake Urchin ( Tripneustes gratilla) is a very colourful and attractive sea urchin that belongs to the Toxopneustidae family. This species is also commonly referred to as a Lamington Urchin. This species has a wide spread distribution through out the waters of the Indo Pacific and is found in the tropical waters of Australia. This species has been recorded from Margaret River in Western Australia around the north to Narooma in southern New South Wales. This species varies greatly in its colour and appearance and its body colour may range between purple, black, brown, red, orange and green. It can be found on rocky and coral reefs, rubble bottoms and in seagrass meadows. The Cake Urchin (Tripneustes gratilla) is known to feed on algae and seagrasses and grows to a maximum diameter of approximately 15cm.