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 Furry Diary remembers it for you
A typical home-care rhythm for a Purple Firefish. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- 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
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at support@furrydiary.app and we will fix it.
- 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.