Firefish Care Guide

Nemateleotris magnifica

DifficultyLow
Minimum Tank Size20 Gallons
DietCarnivore
Water Parameters72-78 F, pH 8-8.4, Salinity 1.020-1.025
AggressionPeaceful
Size3"

From the Indian and Pacific Ocean, Firefish are a great fish to have in a peaceful marine tank. Caring for them is easy however they need to feel safe in the tank. They are very shy and will spend a lot of their time hidden behind any cover they can find, especially when paired with more aggressive fish. This behavior is why they are often called dartfish, as they will quickly dart into cover throughout the day. This trait, when combined with their white body and colored tail makes for a nice addition to the tank.

Behavior & Aggression

One of the biggest issue new owners will have with this fish is its shyness. When added to the tank you will almost never see the Firefish. It will likely spend the first few days hidden, only taking a few glances at the tank. Even when added as the first fish to a recent new tank of mine the fish was in hiding for the entire first day, only coming out for a short bit during the scheduled powerhead off feeding time.

Firefish will often rest or swim in place facing the current in search of food. Additionally they will keep an eye on anything that moves, running for cover if they don’t feel safe. This makes them easy to feed once they are settled into the tank, as even when the powerheads are on they will find food in the moving currents. They favor hanging around the reefs in the wild, making them favor coral areas in the tank. They will also be in contact with the bottom of the tank semi-often, so be sure to use soft substrate so that you do not damage their body.

While they will usually find enough hiding spots inside the rock structure of the tank, Firefish can dig under the rocks to create even more hiding spots for themselves. This is a slow process and isn’t usually noticeable until you see them dart into their hole. If you do not have a lot of unoccupied hiding spots in the rocks of your tank you should either add more rocks or rearrange them to create more hiding spots.

When hiding the Firefish is able to use its long dorsal fin to hold itself in place. They will also use the fin to signal other Firefish, which can often be seen when they see their reflection.

While they do interact with other Firefish, you should only have multiple fish if you either:

  • Buy them as a mated pair
  • Have a very large tank

Firefishpair somewhat similarly to clownfish. They do not like others of their own kind unless it is their partner and can get territorial with fish that look identical to them. Having multiple Firefish seeking hiding spots in a small tank is never a good idea.

Diet & Feeding

These fish are really easy to feed. They will usually be facing the current looking for prey to blow towards them. The Firefish should be fed meaty foods like mysis shrimp, brine shrimp, finely diced seafood and prepared foods. They will also hunt for any algae and zooplankton that is already in the tank.


A comfortable Firefish during feeding time.

There are two important notes to feeding Firefish.

The first is that they are not competitive eaters. Other quick fish such as wrasse can out compete the Firefish, leaving it with very little to eat. This can be solved by having multiple feeding zones, one where the free swimming fish will find and one where they shy firefish will frequently be.

The second note is their small stomachs. Firefish should be fed twice a day to stay healthy. In larger tanks they may be able to hunt enough in the tank to help sustain their diet, but relying on that is not a good idea. Most fish will pick at the tank for foods just like the Firefish will. If you use automatic feeders you may need to schedule them to do two smaller feedings, but you should watch these take place the first few times. If too little food is dispensed the quick eaters may switch over to the Firefish’s area and eat the food that was meant for them.


This video is a perfect example of how shy firefish can be in the tank. They will hide inside the rocks when they don’t feel completely secure. Hiding spots like these are how you can go weeks without seeing them.

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