Sand Sifting Starfish

Sand Sifting Starfish (Archaster typicus): 1. Appearance & Identification Coloration: Features a pale cream, gray, or tan body patterned with distinct darker brown or grayish bands and patches along its five tapered arms, providing natural camouflage against soft substrates. Morphology: Possesses a broad central disc, a slightly inflated body, and neat parallel rows of small armor plates covering its arms, distinguishing it from similar-looking sea stars. Size: Adults typically grow to a diameter of about 4 to 8 inches (12 to 20 cm). 2. Native Origin & Habitat Geography: Widely distributed throughout the tropical Indo-Pacific region, including the Indian Ocean, Philippines, Indonesia, Australia, and parts of Japan. Environment: Found inhabiting shallow coastal waters, sandy lagoon floors, silty bottoms, and seagrass beds, where they spend a significant amount of time buried beneath the sediment. 3. Tank Requirements Minimum Tank Size: Requires a large system of at least 100 gallons with a broad, expansive footprint to ensure an adequate supply of natural food. Substrate Requirements: A fine sand bed (1 to 2 inches deep) is mandatory, reef grade aragonite is suitable. They constantly burrow into the substrate to feed and hide. Coarse crushed coral, sharp gravel, and bare-bottom tanks are completely unsuitable. Water Parameters & Acclimation: Thrives in stable marine conditions (Temperature: 72°F–82°F, Specific Gravity: 1.023–1.026). They are exceptionally sensitive to sudden changes in salinity, pH, and temperature, requiring slow and careful drip-acclimation. 4. Diet & Feeding Behavior Natural Diet: Carnivorous scavengers and micro-predators that feed on detritus, small mollusks, worms, crustaceans, and beneficial microfauna living within the substrate. The Starvation Risk: They are not simple algae eaters. Because they consume beneficial sandbed infauna, they will slowly exhaust the natural food supply in smaller or immature aquariums, frequently leading to long-term starvation. They should only be added to thoroughly mature, well-established systems (typically 6+ months old) with a robust, living sandbed. 5. Reef Compatibility Status: Reef Safe Behavior: They are peaceful toward corals, fish, and sessile invertebrates, and will not directly consume healthy coral tissue. However, their continuous tunneling and sand-shifting can occasionally bury or shift unsecured coral frags placed directly on the sandbed, and they may consume beneficial micro-organisms in the substrate. 6. Temperament & Tank Mates Temperament: Peaceful, slow-moving, and active. They frequently glide across the sandbed or climb low rock structures, especially after lights out. Compatibility: Excellent companion for peaceful community fish, clownfish, gobies, tangs, and blennies. Avoid housing them with animals that prey on echinoderms or aggressive bottom-dwellers that might outcompete them. Generally, only one specimen should be kept per tank unless the system is exceptionally massive.