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Fish · Firefish

Firefish Goby

Nemateleotris magnifica Fowler, 1938

Also called Firefish, Fire Goby, Fire Dartfish, Magnificent Dartfish, Magnificent Firefish, Red Fire Goby

  • CareEasy
  • Reef safeYes
  • TemperamentPeacefulPeaceful; only squabbles with its own kind
  • Favorite foods
    1. Mysis shrimp
    2. Enriched brine shrimp
    3. Copepods / zooplankton
  • Max size3 in (7.6 cm)
  • Min tank30 gal
  • LifespanNot scientifically documented
  • IUCN statusLeast Concern
Firefish Goby (Nemateleotris magnifica)
Species photo: Rickard Zerpe, CC BY 2.0, via Wikimedia Commons

Quick answers

How big does the Firefish Goby get?
Up to 3 in (7.6 cm).
What size tank does it need?
At least 30 gallons.
How hard is it to keep?
Care level: Easy.
Is it reef safe?
Yes. Ignores corals, clams, shrimp, crabs and snails.
What does it eat?
  • Mysis shrimp
  • Enriched brine shrimp
  • Copepods / zooplankton
How long does it live?
Not scientifically documented.
What are good tankmates?
  • Clownfish
  • Royal gramma and other basslets
  • Cardinalfish
  • Small peaceful gobies and blennies
  • Chromis

The 30-second version

The firefish is a small, slim fish that looks like it was dipped in paint. Its head is yellow. Its middle is white. Its back end is bright orange-red, like the tip of a lit match. On its back it has one very tall fin. It flicks this fin up and down like a little flag. In the sea, firefish float just above the reef. They face into the moving water and snap up tiny animals that drift past. If something scary comes, they zoom head-first into a hole in the rocks or sand. Firefish are gentle. They leave corals and other fish alone. But they get scared easily, and a scared firefish can jump right out of the water. So its tank always needs a lid.

Water & care

Hardy and quick to accept frozen and prepared foods, which is why it is a classic first reef fish. Success comes down to four things: a tight lid with no gaps (most losses are jumpers); caves and bolt-holes it can dive into; peaceful tankmates that will not bully it or eat all the food first; and small meaty meals two or three times a day. Keep one per tank or a known pair; two unrelated adults usually fight. Small groups are possible only in large tanks with all fish added at once. New fish often hide for a few days and become bolder once they trust their bolt-hole; dim or shaded areas help.

ParameterKeep it at
Temperature 72–78 °F
Salinity (SG) 1.020–1.025
pH 8.1–8.4
Alkalinity 8–12 dKH
Nitrate 0–20 ppm

Ranges are the standard marine-fish values given by LiveAquaria and Quality Marine and fit the wild temperature range in FishBase (22-28 °C). The fish has no special calcium, magnesium or phosphate needs; in a reef tank set those for your corals. Stability matters more than hitting exact numbers.

Feeding

DietCarnivore

Favorite foods

  • Frozen mysis shrimp
  • Vitamin-enriched brine shrimp
  • Frozen copepods or Calanus
  • Finely chopped seafood (shrimp, clam)
  • Small slow-sinking pellets

Feed small portions two or three times a day, released into the current where it hovers so food drifts past it like plankton. It does poorly on one large, infrequent meal. Vitamin-enriched foods help keep its colour bright. Make sure food reaches it before faster tankmates eat everything; target-feed with a pipette if needed. Avoid large chunks it cannot swallow.

Tank & maintenance

Minimum tank
30 gallons
Aquascape
Live rock with several caves, overhangs and bolt-holes, plus a patch of sand and rubble a few inches deep where it can make a burrow. Leave open water in front of the rocks for hovering. A tight-fitting lid or mesh screen with no gaps (including overflow and equipment cut-outs) is essential.
Lighting
Any reef lighting. It is shyer under very bright light and settles in faster when shaded caves are available.
Water flow
Moderate. It faces into a steady current to pick off food; avoid areas of violent flow around its burrow.

Routine upkeep

Normal reef upkeep: regular partial water changes, stable salinity and temperature, and a weekly check that the lid, screens and overflow covers have no gaps. Watch at each feeding that it comes out and eats, and keep its caves clear so shifting rock does not trap it.

Temperament & tankmates

TemperamentPeaceful

Peaceful toward other species. Intolerant of its own kind except a mated pair, and may squabble with other firefish or dartfish in small tanks. Timid, so it is easily bullied by dottybacks, aggressive damselfish and large wrasses, and may stop feeding if harassed.

Reef safeYes

Ignores corals, clams, shrimp, crabs and snails. It does not nip polyps and only moves a little sand or rubble at its burrow. The main reef-tank concern is the reverse: it can be eaten or harassed by large predatory fish and invertebrates.

Good tankmates

  • Clownfish
  • Royal gramma and other basslets
  • Cardinalfish
  • Small peaceful gobies and blennies
  • Chromis
  • Small peaceful wrasses (fairy and flasher wrasses)
  • Corals, clams and reef invertebrates

Avoid

  • A second firefish, unless it is a known mated pair
  • Dottybacks and aggressive damselfish
  • Large predators that can swallow it (groupers, lionfish, eels, large hawkfish, triggerfish)
  • Very fast, greedy feeders that leave it no food

Help it thrive

  • Cover every gap: lids, mesh screens and overflow openings. Jumping is the number one cause of death.
  • Add it before, or together with, more boisterous fish so it can claim a cave first.
  • Feed small meals two or three times a day into the current, and target-feed if tankmates are greedy.
  • Keep the lights low for the first day and give it shaded bolt-holes; it gets bolder once it feels safe.
  • Keep one per tank unless you buy a confirmed pair.

Common ailments

Marine ich (Cryptocaryon irritans)
Signs
White salt-grain spots on body and fins, scratching against rocks, fast breathing, hiding.
Prevention
Quarantine new fish for several weeks before they enter the display; keep stress low and water stable.
Treatment
Treat in a separate hospital tank (for example a copper medication used exactly as the product's directions say, with daily copper tests, or tank-transfer); never medicate a reef display. Leave the display without fish for about 10-12 weeks so the parasite dies off.

Marine velvet (Amyloodinium ocellatum)
Signs
Dusty gold or grey sheen on the skin, very rapid breathing, clamped fins, hiding, and sudden deaths, often across several fish.
Prevention
Quarantine every new fish; velvet spreads through the water and kills quickly.
Treatment
Move all fish to a hospital tank and treat promptly with a copper medication, following the product's directions and testing copper daily; leave the display fishless for at least 10-12 weeks. Get expert advice early because velvet moves fast.

Stress, bullying and starvation
Signs
Constant hiding, pinched belly, faded colour, torn fins, refusing food at feeding time.
Prevention
Choose peaceful tankmates, keep only one firefish (or a pair), provide many bolt-holes and feed small meals several times a day.
Treatment
Remove or rehome the bully, target-feed enriched foods, and watch torn fins for secondary bacterial infection; treat infections in a hospital tank.

This is general hobby guidance, not veterinary advice. Quarantine new arrivals and treat in a separate tank whenever you can.

Risks of owning one

  • Jumping: an uncovered or partly covered tank is very likely to lose it; hobby guides describe it as almost guaranteed to jump from an open tank.
  • Two firefish that are not a pair usually fight, and the loser may be killed or starve while hiding.
  • Timid: in a tank of aggressive or fast-feeding fish it can be bullied and slowly starve.
  • Nearly all specimens are wild-caught, so buy from suppliers who acclimate and feed fish before sale.

Breeding

DifficultyVery hard Captive-bredRare or wild-caught

Pairs are monogamous and spawn demersal eggs inside a burrow or hole in the substrate. A home-aquarium pair supplied to the University of Florida (UF/IFAS) Tropical Aquaculture Lab spawned about once a month, with about 3,000-6,000 eggs per spawn. The lab reared larvae to 52 days post-hatch on copepod nauplii, but they had not settled by then and losses were high when the diet was switched to Artemia; settlement was expected at about 65-70 days (2019 report). No reliable commercial captive-bred supply was found.

  1. Buy a confirmed pair, or let a pair form from a few juveniles in a large tank and rehome the rest.
  2. Give the pair a quiet tank with a sand and rubble bed and a cave, tube or burrow site.
  3. Condition with frequent, varied, vitamin-enriched meaty foods.
  4. Watch the burrow for eggs; demersal eggs stay inside, so plan how to collect larvae at hatching.
  5. Feed newly hatched larvae copepod nauplii (UF/IFAS used about 5 nauplii per mL twice a day).
  6. Move to Artemia and micro-pellets cautiously and late, since the switch to Artemia caused heavy losses.
  7. Expect a larval period of two months or more before settlement.

Deep dive The science, history and family tree

The science

Nemateleotris magnifica is a small dartfish (Gobiidae: Ptereleotrinae) that reaches about 9 cm total length. The body is elongate and slightly compressed. The head and nape are yellow, the front of the body white to pale pink, shading to bright orange-red over the rear half, and the second dorsal, anal and tail fins are red-orange with dark edges. The first dorsal fin is a tall, pennant-like spine that the fish flicks almost constantly as a signal to other firefish; raised inside a crevice it is reported to help wedge the fish in place. The species ranges across the Indo-Pacific from East Africa to the Hawaiian, Marquesan and Pitcairn islands, north to the Ryukyu Islands and south to New Caledonia and the Austral Islands, including most of Micronesia. Adults live on the upper parts of outer reef slopes. They are recorded to 70 m but are usually found between about 6 and 28 m, hovering a short distance above a burrow or hole in sand, rubble or reef and facing into the current to pick zooplankton, chiefly copepods and crustacean larvae, out of the water. Adults are usually seen alone or in pairs, while juveniles often share a hole in small groups. The species is monogamous, and pairs lay demersal eggs inside a burrow. When threatened the fish darts head-first into its refuge. It is assessed as Least Concern by the IUCN, is harmless to people, and has no fisheries value apart from the aquarium trade, where it is usually the least expensive and most easily obtained member of its genus.

Appearance
Slender fish with a yellow face, a white front half that blushes pink, and a fiery orange-red rear half; the rear dorsal, anal and tail fins are red with dark margins, and the first dorsal fin is a very tall spine that is flicked constantly. Look-alikes: the purple firefish (Nemateleotris decora) has a purple head and purple, red and orange striped fins; Helfrich's firefish (N. helfrichi) and the lavender-blushed firefish (N. lavandula) are lavender to pink with yellowish heads and are rarer and pricier; Ptereleotris dartfishes (e.g. zebra and blackfin dartfish) are longer and plainer and lack the tall pennant fin. No line-bred colour morphs are sold.
Native range
Indo-Pacific: East Africa east to the Hawaiian, Marquesan and Pitcairn islands; north to the Ryukyu Islands (Japan); south to New Caledonia and the Austral Islands; throughout Micronesia. The type locality is Buka Buka Island, Sulawesi, Indonesia.
Habitat
Upper parts of outer reef slopes, recorded from near the surface to 70 m but usually about 6-28 m. Hovers just above a burrow or hole in sand, rubble or reef, facing into the current to feed on passing zooplankton, and retreats head-first into the hole when threatened. Adults live singly or in pairs; several juveniles may share one hole. Water temperature in its range is about 22-28 °C (72-82 °F).
Size
3 in (7.6 cm). Maximum 9 cm (3.5 in) total length per FishBase; aquarium specimens are usually 2-3 in and rarely exceed 3 in.
Lifespan
Not scientifically documented. Hobby sources suggest roughly 3 years for Nemateleotris firefish, and losses are usually from jumping or bullying rather than old age.
Conservation
Least Concern. IUCN Least Concern (FishBase lists an assessment dated 18 August 2023). Not listed by CITES or CMS. Aquarium specimens are wild-collected across the Indo-Pacific; no commercial captive-bred supply was found, though university trials have raised larvae part of the way

In the aquarium vs in the wild

In your aquarium

A small, colourful, peaceful display fish for nano and community reef tanks. It hovers in open water, so it is visible and lively, but it does no clean-up or algae work.

On the reef

A zooplankton picker on outer reef slopes that turns tiny drifting crustaceans into food for larger reef predators.

History

Henry Weed Fowler described Nemateleotris magnifica in 1938, creating the genus Nemateleotris for it at the same time. The description appeared in his report on new fishes collected by the US Bureau of Fisheries steamer Albatross, chiefly in Philippine seas and adjacent waters, and the type locality is Buka Buka Island, Sulawesi. The genus name joins the Greek nema (thread) to Eleotris, an older goby-like genus, and magnifica is Latin for magnificent. Firefish were long placed in the dartfish families Microdesmidae or Ptereleotridae before molecular studies moved dartfishes inside Gobiidae. In the aquarium hobby it has long been a staple of reef and nano tanks, prized for its colour, small size and peaceful nature, and it is usually the cheapest and easiest firefish to find. Captive breeding is still experimental: hobbyists have seen pairs spawn, and in 2019 the University of Florida reported larvae reared to 52 days.

Evolution & relatives

Firefish are dartfishes, a group of hovering, plankton-eating gobies now ranked as the subfamily Ptereleotrinae within Gobiidae, the true gobies. They were once given their own family, but molecular studies placed them inside the goby family and current classifications follow that, although their exact branch within it is still poorly resolved. Their closest relatives are the other Nemateleotris species: the purple firefish (N. decora) and its Indian Ocean twin N. exquisita, and Helfrich's firefish (N. helfrichi) and the lavender-blushed firefish (N. lavandula), which were separated in 2023 on colour, body proportions and about 1% difference in mitochondrial DNA. Next come the Ptereleotris dartfishes. Bottom-sitting shrimp gobies such as the yellow watchman goby are in the same family but on a different branch (Gobiinae). The goby order Gobiiformes, which also includes cardinalfishes, is an early branch of the percomorph (spiny-finned) fishes estimated to have split off in the Cretaceous; the oldest goby skeletons are from the Early Eocene, and the modern goby families diversified around the Eocene-Oligocene transition.

Family tree, from kingdom down

  1. Kingdom Animalia Animals Animals are living things made of many cells that must eat food to live. Fish, corals, crabs, snails and sea stars are all animals.
  2. Phylum Chordata Chordates Chordates have a stiff rod running down their back at some point in their lives. In fish and people, this rod is replaced by a backbone.
  3. Subphylum Vertebrata Vertebrates Vertebrates are animals with a backbone and a skull. Fish, frogs, birds and people are all vertebrates.
  4. Infraphylum Gnathostomata jawed vertebrates
  5. Parvphylum Osteichthyes bony fishes
  6. Gigaclass Actinopterygii ray-finned fishes
  7. Superclass Actinopteri
  8. Class Teleostei Teleost fishes Teleosts are bony fishes with thin, bendy fin rays and jaws that can push forward. Almost all of the fish in the world are teleosts.
  9. Order Gobiiformes Gobies and kin This order includes gobies and sleepers. Most are small fish that live on the bottom, and many share burrows or perch on rocks.
  10. Suborder Gobioidei gobies and sleepers
  11. Family Gobiidae Gobies Gobies are one of the biggest families of fish. Most are small and live on the bottom, and many share burrows with shrimp.
  12. Subfamily Ptereleotrinae dartfishes
  13. Genus Nemateleotris Firefishes Firefishes are slim, colorful fish with a tall front fin that they flick up and down. They dive into a burrow when scared.
  14. Species Nemateleotris magnifica

See it on the Tree of Life Compare with another species

Closest relatives

  • Nemateleotris decora Purple Firefish Same genus; deeper-water western Pacific species with a purple head Read guide · Compare
  • Nemateleotris helfrichi Helfrich's Firefish Same genus; French Polynesia and nearby islands
  • Nemateleotris lavandula Lavender-blushed Dartfish Same genus; described in 2023, formerly confused with N. helfrichi
  • Nemateleotris exquisita Exquisite Firefish Same genus; Indian Ocean and Red Sea relative of the purple firefish
  • Ptereleotris zebra Zebra Dartfish Same subfamily (dartfishes); also described by Fowler in 1938
  • Ptereleotris evides Blackfin Dartfish Same subfamily (dartfishes)
  • Cryptocentrus cinctus Yellow Watchman Goby Same family (Gobiidae), different subfamily (Gobiinae) Read guide · Compare

Fun facts

  1. Its tall front dorsal spine is reported to work like a doorstop: raised inside a crevice, it helps lock the fish in place, much like a triggerfish's spine.
  2. The constant flicking of that fin is a signal to other firefish.
  3. Young firefish often share one hole, but adults pair off and stay together.
  4. The zebra dartfish, a close cousin, was named by the same scientist, Henry Weed Fowler, in the same year, 1938.
  5. A pair in a home aquarium laid about 3,000-6,000 eggs per spawn, roughly once a month.

Learn more

Sources

  1. FishBase: Nemateleotris magnifica summary fishbase.se
  2. FishBase: Nemateleotris decora summary (genus etymology) fishbase.se
  3. WoRMS: Nemateleotris magnifica Fowler, 1938 marinespecies.org
  4. Wikipedia: Nemateleotris magnifica en.wikipedia.org
  5. Wikipedia: Nemateleotris en.wikipedia.org
  6. Wikipedia: Ptereleotrinae en.wikipedia.org
  7. Wikipedia: Goby (classification and fossil record) en.wikipedia.org
  8. Wikipedia: Gobiiformes en.wikipedia.org
  9. TFH Magazine: Nemateleotris magnifica tfhmagazine.com
  10. LiveAquaria: Firefish liveaquaria.com
  11. Quality Marine: Firefish qualitymarine.com
  12. Quality Marine: The Fire in the Fish Tank qualitymarine.com
  13. Quality Marine: Meet Nemateleotris lavandula qualitymarine.com
  14. Rising Tide Conservation: UF/IFAS TAL fire goby aquaculture (2019) risingtideconservation.org
  15. Randall & Connell 2013, Nemateleotris exquisita (J. Ocean Sci. Found. 8) oceansciencefoundation.org
  16. Saltwater Aquarium Blog: Purple firefish (Nemateleotris lifespan note) saltwateraquariumblog.com

Care facts

The care facts on this guide and its product pages (care level, reef safety, temperament, size, tank, diet, flow, purpose, foods, acclimation and origin) combine 12 independent sources, checked October 25, 2026.

  1. Nemateleotris magnifica summary FishBase
  2. Firefish Goby LiveAquaria
  3. Saltwater Firefish Goby Quick Facts, Care Guide, Diet and More Saltwater Aquarium Blog
  4. Red Firefish Goby - Nemateleotris magnifica That Pet Place
  5. Firefish Goby Care Sheet: Setup, Feeding, & More Build Your Aquarium
  6. Nemateleotris magnifica Reef Exclusive
  7. Nemateleotris magnifica Tropical Fish Hobbyist
  8. Firefish Goby :: 18519 Quality Marine
  9. Firefish Goby Care: Tank, Diet & Tankmates Top Shelf Aquatics
  10. Firefish Goby Care: Diet, Diseases, Tank Mates & Size Aquarium Source
  11. Firefish: Saltwater Aquarium Fish for Marine Aquariums LiveAquaria
  12. Species Spotlight: Red Firefish Goby Frags 2 Fishes

Scientific names and classification follow the World Register of Marine Species (AphiaID 219611). Last updated October 25, 2026.