Coralkin honest saltwater & reef care

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Firefish Goby

Nemateleotris magnifica

An elegant, peaceful hover-fish with a flame-orange tail — perfect for nano reefs.

Difficulty: Beginner Reef-safe community fish Reef-safe

Illustration of a Firefish Goby

The firefish (Nemateleotris magnifica) is an elegant, peaceful hover-fish — white up front, flame-orange at the tail, with a flicking dorsal fin. It's perfect for a nano reef and utterly reef-safe. The catch: it's a champion jumper, so a tight lid isn't optional.

Good to know: A notorious JUMPER — needs a tight lid.
📊 What keepers actually ask: The #1 firefish story keepers tell is finding one on the floor — so we lead with the lid.

Care at a glance

Adult sizeSmall — about 2–3 in (5–8 cm).
LifespanAbout 3 years.
Minimum tankA 20–30 gallon reef (commonly kept in nanos); moderate flow and rockwork to bolt into.
Temperature75–82°F (24–28°C).
pH8.1–8.4.
Specific gravity1.020–1.026 (≈35 ppt; keep it stable).
Other targetsGive it a rockwork retreat/burrow; keep nitrate low.
DietPlanktivore — frozen mysis and brine shrimp, blackworms, and prepared marine foods; small feeds a couple of times a day.
TemperamentPeaceful and rather timid toward other fish — but territorial toward its own kind. Keep one, unless you have a proven bonded pair.
Reef-safeYes — leaves corals and inverts alone.
Natural rangeIndo-Pacific reefs.
Beginner-friendly, done right. Hardy, peaceful and cheap — a great early fish for a calm community or nano. The two things that catch people out are jumping (needs a sealed lid) and keeping two (they fight unless bonded). Solve those and it's easy.
What does a firefish goby really cost? The firefish goby itself is usually the cheapest part — the reef system is the real cost. See the honest firefish goby cost breakdown (upfront vs ongoing, and where it's safe to save). No prices quoted.
Planning your stock list? Before you buy, run your tank and wish-list through our free stocking & tank-size calculator — it checks this fish's minimum tank and shoal size and flags any aggression clash, so you don't overstock.

The fish store gets these wrong

Common myths, kindly corrected — no shame for having believed them.

  • “A little gap in the lid is fine.” Not for a firefish — they slip through surprisingly small openings. You need a tight-fitting lid or mesh over every gap.
  • “Keep a few for a shoal.” No — firefish are territorial with their own kind. Keep a single unless you buy a proven bonded pair.

Before you buy

  • Seal the tank — a tight lid or mesh over every opening.
  • Add it among peaceful fish; it's timid and gets outcompeted by boisterous tankmates.
  • Give it rockwork to dart into.
  • One firefish (or a bonded pair only).

Quarantine and get help if…

We can't diagnose from a photo — but these are the signs to stop watching, quarantine, and get an aquatic vet or an experienced reefer's eyes on it:

  • White salt-grain spots, flashing, or rapid gill-breathing (possible ich or velvet).
  • Cloudy skin patches, clamped fins, or gasping at the surface.
  • Refusing food and hiding for days, or a hollow belly.
  • Any new fish added without quarantine.

Print the Firefish Goby emergency vet-prep card — what to bring, what to tell the vet, and the questions to ask.

Never

  • Never run an open-top tank with a firefish — it will jump.
  • Never keep two (non-bonded) firefish together.
  • Never house it with aggressive or boisterous fish that bully it off its food.
  • Never add it to an uncycled tank.

Common firefish goby questions

Do firefish jump?

Yes — notoriously. Firefish are among the most enthusiastic jumpers in the hobby and slip through small gaps. A tight-fitting lid or mesh cover over every opening is essential.

Can I keep more than one firefish?

Only a proven bonded pair. Firefish are territorial toward their own kind, so two unbonded fish usually fight — keep a single otherwise.

Are firefish reef-safe?

Completely. They leave corals and invertebrates alone and are a classic peaceful nano-reef fish.

What size tank does a firefish need?

A 20–30 gallon reef is plenty, and they're commonly kept in nanos. Give them rockwork to bolt into and, above all, a sealed lid.

How long do firefish live?

Around 3 years is typical in the aquarium.

🐚 Did you know? — Firefish Goby fun facts

Little true delights about the firefish goby — each one checked against a named source, no reef-store folklore.

  • The firefish hovers just above the seabed facing into the current, waiting for tiny drifting invertebrates to arrive. Wikipedia
  • A firefish constantly flicks its very long first dorsal fin back and forth as a signal to other firefish. Wikipedia
  • Firefish are monogamous, living in sandy burrows alone or in pairs and darting back inside the moment they feel threatened. Wikipedia

More reef fun facts →

Sources & further reading

This guide was written and fact-checked against these authorities. It's honest, general guidance — not a diagnosis, and not a substitute for an aquatic vet or your own test kit:

Written and fact-checked by The Coralkin Team against marine-aquarist and veterinary sources — if your firefish goby shows a red-flag sign above, quarantine and get an aquatic vet or an experienced reefer's eyes on it. We never guess a care number.

🔬 Review status: team-written and fact-checked against cited sources · not yet reviewed by a marine vet. How we research & fact-check →

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