Helfrich's firefish

Geographical Origin and Habitat: Western and Central Pacific Ocean: from Japan to Samoa and French Polynesia. Inhabits steep outer reef slopes and drop-offs at depths of 25 to 90 meters.

Taxonomy and Morphology: Member of the Microdesmidae family. The smallest member of the Nemateleotris genus, reaching about 6 cm (2.4 inches) in adult size.

Social Behavior: Extremely shy, peaceful, and hovering. Lives in monogamous pairs. Hovers against currents close to its shelter to catch passing food.

Coloration and Sexual Dimorphism: Soft lavender body contrasting with a neon yellow face. A purple stripe runs across the forehead. No sexual dimorphism.

Aquarium Setup: Minimum aquarium size of 80 liters (20 gallons). Provide plenty of live rock with tiny caves. A secure, tight mesh cover is mandatory to prevent jumping.

Diet and Feeding: Carnivorous. Feeds on zooplankton in the water column. Offer frozen copepods, marine eggs, finely chopped mysis, and micro pellets.

Water Quality: Prefers slightly cooler temperatures (22-25°C / 71-77°F) due to deep-water origin. Maintain pH 8.1-8.4, specific gravity 1.020-1.025, and KH 8-12.

Compatibility and Cohabitation: Peaceful and timid. Avoid housing with aggressive, territorial, or fast competitors. Keep singly or in mated pairs. Reef safe.

Aquarium Breeding: Unrecorded in domestic systems due to challenges in pelagic spawning and larval nutrition.

Risks and Diseases: High jumping risk. Shyness can lead to starvation if housed with aggressive species. Quarantine is highly recommended.