Helfrichi Firefish (Nemateleotris helfrichi) Care Guide
A stunning and highly prized dartfish with a lavender-purple body and a bright yellow forehead. One of the most beautiful and expensive nano reef fish.
Compiled by Aquairi from published sources · Published · Updated
Overview
Nemateleotris helfrichi is a species in the family Ptereleotridae. A stunning and highly prized dartfish with a lavender-purple body and a bright yellow forehead. One of the most beautiful and expensive nano reef fish. Shy and peaceful, requiring a calm environment and a tight lid to prevent jumping. Best kept in mated pairs.
Taxonomy
- Family: Ptereleotridae
- Genus: Nemateleotris
- Scientific name: Nemateleotris helfrichi
- Other names: Helfrich's Dartfish
- Origin: Pacific Ocean
Habitat
Restricted to deeper reef slopes of the central Pacific from the Mariana Islands and Marshall Islands east to French Polynesia. Hovers above coral rubble at depths of 25-90 m; the deep-water habitat makes wild collection technically demanding and the species commands the highest prices among Nemateleotris.
Tank requirements
- Minimum tank volume: 80 L
- Temperature: 24-27 °C
- pH: 8.1-8.4
- GH: 8-12 °dGH
- Water flow: low
- Adult size: 5-7 cm
- Lifespan: 3-5 years
- Difficulty: intermediate
Diet
Classified as carnivore. Recommended feeding frequency: 2x daily. In captivity, offer a varied diet appropriate to the species — quality prepared foods supplemented with frozen or live items of suitable size.
Compatibility
- Temperament: peaceful
- Swimming level: middle
- Compatible tank mates: Clownfish, Royal Gramma, Blennies
- Avoid with: Aggressive Fish, Other Dartfish
Reef compatibility
Generally classified as reef-safe: does not feed on stony or soft corals, tridacnid clams or ornamental shrimps under normal conditions.
Breeding
- Breeding difficulty: advanced
Helfrichi Firefish (Nemateleotris helfrichi) Breeding Guide
Overview
Nemateleotris helfrichi is a small dartfish (family Ptereleotridae) of the southeastern Pacific around French Polynesia, reaching about 6 cm. It inhabits small patches of sand, rubble or hard bottom on steep seaward reefs, rarely found shallower than 40 m, where it feeds on zooplankton and frequently occurs in pairs (FishBase). It is oviparous and monogamous, but its pelagic larvae make it rarely if ever bred at home.
Sexing
Reliable external sexing is not documented in the consulted sources. The species frequently occurs in pairs, reflecting its monogamous social structure, so a bonded pair is recognized behaviorally rather than by fixed markings (FishBase).
Breeding Setup
A calm aquarium with sand, rubble and rockwork for shelter suits a bonded pair. Like other firefish it is a jumper, so a secure lid is essential. The species naturally occurs on deep reefs and prefers a quiet, low-flow environment with stable reef parameters.
Spawning Behavior & Trigger
The species is oviparous with monogamous mating observed as both obligate and social, but detailed spawning behavior and fecundity are not elaborated in the consulted scientific sources (FishBase). Dartfish of this group are not established as home-bred species.
Egg & Fry Care
Specific egg and fry data for Nemateleotris helfrichi are not documented in the consulted sources. Gobioid reef larvae of this type are small and pelagic, requiring tiny live first foods, and no reliable home rearing protocol is published for this species.
Common Challenges
The absence of documented spawning and rearing methods, the pelagic larvae, and the species' jumping behavior make home breeding impractical. A bonded pair can be kept in a securely covered, calm system, but reproduction to settlement is not established.