Purple Firefish (Nemateleotris decora)

The Purple Firefish (Nemateleotris decora), also known as the Elegant Firefish or Decorated Dartfish, is a stunning marine fish admired for its beautiful blend of purple, violet, yellow and white colouration. Its pale body contrasts with a vibrant purple head and darker rear markings, while its elongated dorsal fin and red-edged fins give it an elegant appearance. This eye-catching species is an excellent choice for peaceful marine and reef aquariums.

Native to the Indo-West Pacific, the Purple Firefish is commonly found around rocky reef slopes and sandy or rubble-covered areas. It often hovers in the water above a burrow or rock crevice, watching for tiny planktonic foods drifting past. In the aquarium, this graceful hovering behaviour adds movement and interest, while its quick darting movements and habit of retreating into cover make it fascinating to observe.

The Purple Firefish is generally peaceful and can be kept with a range of calm marine fish, corals and ornamental invertebrates. It is naturally shy, however, and may struggle when housed with aggressive or boisterous tankmates that compete for food. Provide plenty of caves, crevices and secure hiding places within stable live rock, along with open swimming space nearby.

A varied, protein-rich diet is essential for maintaining its health and vibrant colouration. Offer small meaty foods such as frozen mysis shrimp, enriched brine shrimp, copepods and other suitable plankton-based preparations. Quality marine micro-pellets may also be accepted. Feed regularly and make sure the Purple Firefish receives enough food, particularly when kept with faster-swimming tank mates.

One of the most important care requirements is a secure, tightly fitting aquarium lid. Purple Firefish are excellent jumpers and can leap from an uncovered tank when startled. They are usually best kept singly or as a compatible, established pair, as unrelated individuals may fight over territory.

With its striking purple markings, graceful swimming style and peaceful nature, the Purple Firefish is a beautiful addition to a mature, well-maintained marine aquarium.

Care at a glance

• Scientific name: Nemateleotris decora

• Common names: Purple Firefish, Elegant Firefish, Decorated Dartfish

• Adult size: Approximately 8–9 cm

• Origin: Indo-West Pacific

• Diet: Carnivore / planktivore

• Temperament: Peaceful and shy

• Reef compatibility: Reef-safe

• Aquarium: Mature marine aquarium with live rock, caves and open swimming space

• Special requirement: Tight-fitting lid to prevent jumping

• Best kept: Singly or as a compatible, established pair

• Experience level: Beginner to intermediate

• Suggested aquarium size: Around 90–100 litres or larger