Threadfin Anthias

Geographical Origin and Habitat: Western Indian Ocean: from East African coasts and South Africa to the Maldives, Seychelles, and Chagos Islands. Inhabits deep outer reefs exposed to strong currents rich in zooplankton at depths of 10 to 30 meters.

Taxonomy and Morphology: Member of the subfamily Anthiadinae. Features a slender body, lyre-shaped tail, and a long extendible filamentous ray on the first dorsal fin. Grows up to 13 cm.

Social Behavior: Peaceful and schooling. Swims in coordinated schools above coral heads. Protogynous hermaphrodite; the dominant female transforms into a male if the male is lost.

Coloration and Sexual Dimorphism: Stunning coloration with pastel pink, red, and orange-yellow hues. Adult males display deeper red colors, longer dorsal filaments, and larger pectoral fins than females.

Aquarium Setup: Requires a tank of at least 250 liters (400+ for harems) with open swimming space against currents. A tight-fitting lid is mandatory as it is a frequent jumper.

Diet and Feeding: Planctivorous carnivore. Demands frequent feeding (3-4 times daily) with small frozen foods like copepods, calanus, mysis, and lobster eggs. Difficult to train on dry foods.

Water Quality: Keep parameters pristine and stable. Temperature 22-27°C, pH 8.1-8.4, salinity SG 1.020-1.026. GH 15-25. Strong water movement is required to stimulate natural behavior.

Compatibility and Cohabitation: 100% reef safe, ideal for SPS setups. Keep in groups consisting of one male and several females (harem). Avoid aggressive or fast competitors for food.

Aquarium Breeding: Extremely difficult in captive environments due to space requirements and planktonic larval feeding needs.

Risks and Diseases: Highly sensitive to prolonged fasting (wasting disease). Demands excellent water sanitation and is prone to parasitic infections under stress.