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Black Longspine Urchin
(Diadema setosum)
Quick Care FactsCare Level: Easy
Temperament: Peaceful
Maximum Size: 3"
Diet: Herbivore
Aquarium Level: All
Minimum Tank Size: 12 gallons
Reef Compatible: Yes
Water Conditions: 72-78° F, dKH 8-12, sg 1.020-1.025, pH 8.1-8.4
Supplements: None
Coloration: Black
Origin: Indo-Pacific
Family: Diadematidae
Species: Urchins
Species Information
The Black Longspine Urchin, is also commonly known as the Long-spined Sea Urchin, and has a body which is predominately black with a red eyespot in the center surrounded by bright blue markings. The spines on these urchins are long, thin and completely black, while they may look like a very delicate species, they are in fact very capable of protecting themselves.
This fact makes the Black Longspine Urchin an excellent algae controllers for an aquarium housing aggressive fish species, where other traditional cleaning crew species; such as, snails and crabs would quickly become a meal for a hungry predator fish. The Black Longspine Urchin is equally at home in the reef aquarium, as it has a peaceful disposition and will not harm other aquarium inhabitants.
Aquarium Care
Since the Black Longspine Urchin is a nocturnal creature it will generally spend much of the daylight hours in caves or crevices in the live rock, then venturing out more at night to scavenge for algae on the aquarium substrate and glass. Therefore, it is important to provide an aquarium with ample hiding places and room to roam.
These urchins are an excellent algae controller for an aggressive aquarium where other invertebrates would be eaten, as when they are approached by a fish, these urchins will sense their presence, and will defend itself by directing its spines towards its offender. While this species is very capable of defending itself, it is not an aggressive species and can live in reef, fish-only or aggressive fish aquariums without problems.
Like most marine invertebrates it is very sensitive to high levels of copper-based medications and will not tolerate high nitrate levels. If it begins to shed its spines, this is a sign of very poor water quality.
Feeding & Nutrition
Black Longspine Urchin are true scavengers, that spend their time scouring live rock, aquarium substrate or even the glass walls of the aquarium looking for algae to eat. Black Longspine Urchin are herbivores and therefore are excellent algae eaters, but will not consume leftover meaty foods. This species is an excellent addition to an aquarium with aggressive fish species; such as, triggers, sharks or groupers as they can protect themselves with their spines and still keep the tank clean by eating the algae.
Thus, the Black Longspine Urchin unlike other algae eating species like snails and crabs, can solve the problem many aggressive species aquarium owners face of how to get rid of unwanted algae growth without there aggressive fish species eating the cleaning crew. If there is not enough algae growth in the aquarium, their diet may be supplemented with dried seaweed.
More InformationCaution The Black Longspine Urchin is venomous, with its sting being roughly equivalent to that of a bee sting. Use care when handling or working around this species in the aquarium.
Additional Photos