Encyclopaedia
Long-spined Urchin
Diadema setosum
A large marine urchin with extremely long, venomous black spines, serving as a highly effective algae controller.
- Family
- Diadematidae
- Origin
- Oceano Indo-Pacifico tropicale
- Origin
- Cosmopolitan or introducedTropical oceans and reefs
- Tank use
- Used in 0 tanks
Share
23 °C - 27 °C
8.1 - 8.4
Marine
Alghivoro
Alta
Species description
Geographical Origin and Habitat: Widely distributed in the tropical Indo-Pacific. Commonly found on shallow coral reefs, rocky areas, and sandy flats.
Taxonomy: Classified under the Diadematidae family. Characterized by a spherical shell (test) and extremely long, hollow, brittle spines.
Social Behavior: Peaceful towards other tankmates. Nocturnal grazer; spends daytime hours wedged in reef crevices and emerges at night.
Coloration and Sexual Dimorphism: Mostly black test and spines with a bright orange ring on the anal cone and neon blue lines. No sexual dimorphism.
Care, breeding and tankmates
Tank Setup: Needs a spacious tank (55+ gallons) with very secure rockwork to prevent the urchin from causing rock collapses.
Diet and Feeding: Voracious herbivore. Eats microalgae, green hair algae, and coralline algae. Feed dried seaweed (nori) if natural algae is low.
Water Quality: Keep salinity constant at 1.023-1.025. Sensitive to water quality drops and nitrogenous waste accumulation.
Compatibility and Tankmates: Generally reef-safe, but may knock over unsecured corals. Do not house with large triggerfish or puffers.
Aquarium Breeding: Broadcast spawner; eggs and sperm are released into the water. Successful captive rearing is rare.
Risks and Diseases: Sharp, venomous, and brittle spines can cause painful stings to aquarists. Avoid touching directly.
Invertebrate profile
- Type
- Sea urchin
- Diet
- Erbivoro
- Ecological role
- Alghivoro
- Minimum group
- 1
- Adult size
- 15 cm
- GH
- n/a
- KH
- 8 dKH - 12 dKH
- TDS
- n/a
- Copper
- Alta
- Shock sensitivity
- Alta
- Calcium and minerals
- Richiede calcio costante per la robustezza del guscio calcareo.
- Molting
- Non muta (echinoderma), ma ricostruisce continuamente le spine perse.
- Reproduction
- Riproduzione sessuata a fecondazione esterna libera, stimolata dai cicli lunari.
- Compatibility & tankmates
- Reef-safe ma può graffiare le alghe coralline. Attenzione a non schiacciarlo contro i coralli.
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
Related species
Other recommended species with similar care requirements and water parameters.
