Common name(s): Black Longspine Urchin, Long-Spined Sea Urchin

Scientific name: Diadema setosum

Family: Diadematidae

Origin: Indo-Pacific

Maximum size: Up to 8"

Care:The Black Longspine urchin is a peaceful, easy to keep invert for your marine aquarium if you have a mature tank with plenty of coralline algae. The urchin is black with very long spines and has irridescent blue spots scattered around it's body. It also has an appendage which looks like a mouth but is the 'other end'. They will continuously graze in your tank. Often you can hear a scraping sound as it rasps away coralline algae. The urchin has long black spines which are not supersharp, but, can poke you if you are not careful when putting your hand in the tank. Most of the time it is shy. My urchin is out and about all day but many may become nocturnal and hide in caves during the day.

Like most inverts, this urchin is sensitive to high nitrates and copper. If it is stressed from poor water quality, it will drop it's spines.

Feeding: Although 'rated' as reef compatible, the Black Lonspine has been accused of eating some softies, including ricordea. Generally, they eat coralline algae, so, if you value the color of your live rock, don't put one in. The urchin's mouth contains a beak-like structure called Aristotle's lantern...very complex. They will also eat seaweed (nori) placed in a veggie clip and eat algae in your tank.

Sexing: Unknown

Breeding: Males and females eject the sperm and eggs into the water where they fertilize and form a tiny urchin. Breeding doesn't occur until an urchin is fully grown, approximately 2 years.

Comments: This urchin is venomous, so, if you have young children in the house, you might want to avoid it. The sting reportedly feels like a bee. The spines can also get stuck under the skin, break off and cause severe irritation. Also be aware that it is TRUE that they can re-arrange your aquascaping if your corals are not battened down.





Aristotle's lantern visible:

Pardon the noise and poor view, but here is a clip of the urchin spawning.
SH
Urchin spawning