The Helfrichi Firefish (Nemateleotris helfrichi), also known as Helfrich’s Dartfish, is a species of dartfish native to the central and western Pacific Ocean. It is one of the most sought-after firefish species due to its striking coloration.

Distribution and Habitat

The Helfrichi Firefish is found in the central and western Pacific Ocean, particularly around the Marshall Islands. It inhabits coral reefs at depths of 25 to 70 meters, typically on hard open bottoms of reefs, sandy patches, and rubble areas where there are strong currents.

Physical Description

The Helfrichi Firefish reaches a maximum length of approximately 6 cm (2.4 in). It has a distinctive coloration with a bright yellow head, a white body, and a purple to pink posterior. The dorsal fin is elongated and the fish flicks it as a signal.

Diet and Feeding

The Helfrichi Firefish feeds on zooplankton, especially the larvae of copepods and crustaceans. In captivity it accepts a varied diet including brine shrimp, mysis shrimp, and frozen preparations.

Behavior and Reproduction

This species is often found in pairs and is monogamous. They will dart into holes when alarmed. They are peaceful and sociable.

Aquarium Care

It is considered reef-safe and peaceful. It requires a tank of at least 20 gallons with a tight-fitting lid as they may jump. It is suitable for nano reef aquariums. It is one of the more expensive firefish species due to its rarity and deep-water habitat.

Conservation Status

Classified as Least Concern by the IUCN Red List.