Red Knobbed Starfish

Geographical Origin and Habitat: Native to the tropical waters of the Indian Ocean, including East Africa, Madagascar, and the Seychelles. Inhabits shallow reefs and sandy flats.

Taxonomy: Member of the Oreasteridae family, genus Protoreaster. Features a robust body with five arms covered in heavy, horn-like red knobs. Diameter reaches up to 30 cm.

Social Behavior: Solitary, active predator. Crawls slowly over the substrate using its tube feet to search for food.

Coloration and Sexual Dimorphism: Body base is cream or grayish-white with contrasting bright red knobs and connecting stripes. No visible external sexual dimorphism.

Tank Setup: Requires a large aquarium of at least 300 liters with open sandy areas and stable rockwork. **Not suitable for reef aquariums containing corals**.

Diet and Feeding: Voracious carnivore. Feeds on soft corals, stony corals, sea anemones, sponges, clams, and other starfish. Supplement with chopped shrimp, clams, and squid.

Water Quality: Specific gravity 1.023-1.025, pH 8.1-8.4, temperature 22°C-26°C. Nitrates must be kept low.

Compatibility and Tankmates: Keep with medium to large, peaceful fish. Do not house with slow invertebrates or predatory fish that eat starfish (e.g. triggerfish).

Aquarium Breeding: Broadcast spawner with external fertilization. Successful reproduction in captivity is undocumented due to pelagic larval requirements.

Risks and Diseases: Rapid tissue necrosis can occur if the starfish is exposed to air or subjected to rapid osmotic changes. Copper is highly toxic.