At a glance the quick version
Looks how to spot one
Slender dartfish with a tall first dorsal fin
A slim, elegant fish with a purple head, a pale white to yellowish body that darkens toward the tail, and fins banded in purple, red, black and orange.23
Personality what they are like
Usually gentle with other fish but can squabble with its own kind unless the two are a mated pair. Quick to dart into a hole if alarmed.321
Daily activity how busy a day looks
Hovers near the bottom to catch passing food and retreats to shelter when startled.12
Grooming and care the hands-on bits
Provide rockwork and loose coral rubble for shelter and a secure lid, since it is a strong jumper. A varied, vitamin-enriched diet helps it keep its strong colours.23
Home where they are happiest
Minimum about 20 US gallons (76 L), suitable for reef and nano reef tanks. In the wild it lives deeper than the common firefish, mostly 25 to 70 m, near reef drop-offs with moderate to strong currents.321
Food basics what goes in the bowl
Carnivore that eats zooplankton such as copepods and crustacean larvae in the wild. Offer chopped seafood, frozen carnivore foods, mysis and enriched brine shrimp.13
Company who they like around
Usually seen in pairs and monogamous. Keep singly or as a mated pair.123
The story where it all began
John Randall and Gerald Allen described the species in 1973. The name decora comes from the Latin for elegant or beautiful. Some researchers treat the western Indian Ocean form as a separate species, Nemateleotris exquisita.412
Fun facts for the dinner table
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 2015)1
The care rhythm a typical week and year
A typical home-care rhythm for a Purple Firefish. A starting point, not a vet's advice.
- FeedingSmall amounts once or twice a dayevery day
- Temperature checkevery day
- Salinity checkevery week
- Top-upTop up evaporation with fresh RO water, not salt waterevery day
- Water testevery week
- Water changeAbout 10 to 20% of the waterevery 2 weeks
- Glass cleanevery week
Owner questions the things everyone asks
How often should I feed my Purple Firefish?
Feed small amounts once or twice a day, as Furry Diary's starting plan suggests. This carnivore enjoys frequent, tiny meals to stay healthy and colourful.31 Pet Wiki plan
What does a Purple Firefish eat, and what should it never eat?
It eats zooplankton like copepods and crustacean larvae in the wild. Offer chopped seafood, frozen carnivore foods, mysis and enriched brine shrimp. Avoid any plant-based foods or large chunks it cannot swallow.31
How much space does a Purple Firefish need?
A minimum of about 20 US gallons (76 litres) is recommended. This fish is suitable for reef and nano reef tanks with plenty of rockwork and loose coral rubble for shelter.321
What temperature, light or water does a Purple Firefish need?
It comes from deeper waters (25 to 70 m) near reef drop-offs with moderate to strong currents. Keep water quality stable with regular temperature checks and weekly salinity tests. Use a secure lid as it is a strong jumper.321 Pet Wiki plan
How often should I clean a Purple Firefish's home?
Furry Diary's plan suggests cleaning the glass weekly and doing a 10 to 20% water change every two weeks. Top up evaporation daily with fresh RO water, not salt water. Pet Wiki plan
Can a Purple Firefish live with others?
Yes, it is usually gentle with other fish but may squabble with its own kind unless they are a mated pair. Keep it singly or as a mated pair for best harmony.321
How long does a Purple Firefish live?
Lifespan varies depending on care and environment. For specific longevity expectations, ask a good breeder or an exotic-pet vet.
Can I handle a Purple Firefish?
Handling is not recommended as it is quick to dart into a hole if alarmed and can be stressed by physical contact. Enjoy watching its graceful movements instead.321
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.
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Where this comes from
Every fact on this page has a numbered source. Spotted an error? support@petwiki.app.
- FishBase: Nemateleotris decora fishbase.seused for distribution, size, depth, habitat, diet, IUCN, name meaning
- Wikipedia: Nemateleotris decora en.wikipedia.orgused for colours, behaviour, aquarium notes, taxonomy
- LiveAquaria: Purple Firefish liveaquaria.comused for care, tank size, diet, temperament
- Wikipedia: Nemateleotris en.wikipedia.orgused for describers and year
Checked 2026-09-30. Text is written in our own words from these sources.