Spotted mandarin goby

Geographical Origin and Habitat: Indo-West Pacific: from the Philippines and Indonesia to northwest Australia. Inhabits sheltered coral reefs and rubble zones.

Taxonomy and Morphology: Member of the Callionymidae family. Cylindrical, scaleless body with large protruding eyes and a small protractile mouth. Grows to 7 cm (2.8 inches).

Social Behavior: Peaceful and slow-moving. Glides over the rockwork in search of food. Males are territorial and will fight aggressively with other males.

Coloration and Sexual Dimorphism: Greenish-blue body covered in concentric target-like rings of black, orange, and green. Males have an elongated first dorsal fin spine.

Aquarium Setup: Minimum aquarium size of 120 liters (30 gallons) with at least 30-40 kg of established live rock (tank running for a minimum of 1 year) to foster copepods.

Diet and Feeding: Extremely difficult. Strictly carnivorous micro-predator. Feeds almost exclusively on live copepods and amphipods. Rarely accepts frozen foods.

Water Quality: Keep standard marine parameters stable: temperature 22-26°C (72-79°F), pH 8.1-8.4, specific gravity 1.020-1.025, and KH 8-12.

Compatibility and Cohabitation: Highly peaceful. Avoid housing with aggressive food competitors or active wrasses that deplete the copepod population. Reef safe.

Aquarium Breeding: Spawns at dusk, executing a vertical mating rise. Raising the pelagic larvae is highly difficult in home setups.

Risks and Diseases: High risk of starvation in new setups. Scaleless skin produces a toxic mucus coat that provides resistance to common parasites.