Firefish Goby (Magnificent Dartfish)

Firefish Goby
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The firefish goby is a terrific little ornamental saltwater fish that makes a great addition to any mini or nano reef tank. This fish's bright colors make it stand out. Owners of this fish say that it has tons of personality. The name "dartfish" comes from this fish's habit of darting quickly back into hiding whenever it feels threatened or frightened. It spends its days flitting around the tank, then neurotically diving into cover. It is an inhabitant of reefs where it can be found at depths from 20 to 230 feet. It is usually found just above the bottom, facing into the current, where it awaits its prey of small invertebrates.

Breed Overview

Common Names: Firefish goby, fire goby, magnificent or fire dartfish

Scientific Name: Nemateleotris magnifica

Adult Size: 3 inches

Life Expectancy: 3 years


Family Microdesmidae
Origin Africa, Coral Sea, Indonesia, Maldives
Social Peaceful
Tank Level All areas
Minimum Tank Size 20 gallon
Diet Omnivore
Breeding Egglayer
Care Easy
pH 8.1 to 8.4
Hardness 8 to 12 dGH
Temperature 72 to 80 F

Origin and Distribution

The firefish goby is native to the Indian and Pacific oceans from the eastern coast of Africa to the Hawaiian Islands and from the Austral Islands north to the Ryukyu Islands. In the wild, this fish can be found in groups hovering above the reef, close to its numerous hiding places, feeding on the planktonic food that drifts by in the current.

Colors and Markings

A firefish goby is a long, slender fish. Its face is yellow, its front half is white, its rear half is red. The dorsal, anal, and caudal fins are highlighted in black. The first spine in the first dorsal is greatly elongated and may be as long as the fish itself. This elongated dorsal fin is used to signal other firefish as well as a "locking device" similar to the triggerfish. This locking device allows the firefish to lock itself into a crevice using its dorsal as a catch.

The fire goby has a swim bladder, which allows it to hover in one location for extended periods with its head pointed upwards. 


The firefish goby is a near-perfect reef tank fish as it doesn't bother other fish, corals, or invertebrates commonly found in a reef tank. It may become territorial if it is crowded in a small aquarium (particularly with members of its own species). Though it may take them some time to become comfortable and active, they often act as "dither fish" and their activity can encourage other shy fish to come out into the open more often. Unless it is part of a mated pair, this fish my quarrel with other fish of the same species.

Potential tankmates may include two gobies of the same species, clownfish, or shrimp gobies. Slow-moving, timid tankmates are recommended. Gobies are easily eaten by triggers, lionfish, and large angels.

Habitat and Care

Because of its size and constant roaming nature, the minimum aquarium size suggested for this fish is at least 20 gallons, but larger would be much better. There should be a strong water flow. Provide at least a minimum of two square feet of bottom surface area per couple if you stock more than two. Most dartfish are too-easily lost by hobbyists because of simple mistakes. Some jump out due to poorly secured aquarium covers. For this reason, house your firefish in an aquarium with a tightly fitting lid. The next largest cause of loss is likely due to stress, damage, and outright predation by inappropriate tankmates. Following closely behind is a lack of nutrition or out-competition for foods. 

This fish is very timid and will not come out of hiding unless it feels secure. Keep the lighting low to moderate. A brightly lit tank may stress out this fish. Firefish gobies like to have a "hiding hole," so provide it with some options for concealment. A suggestion is to trim a piece of PVC pipe, which can serve as a cave-like hideout. Then, create a facade of rock around it. The PVC doesn't have to show, and you can provide your fish a safely reinforced cave that will not cave in with your little fine-finned friend inside it. Another way it likes to hide is it will dig itself in the sand, so use fine aquarium sand or smooth, small pebble substrate. The substrate selected should not be too rough; you do not want to damage its fins or body. 

When the firefish goby is first introduced into a tank it may hide for days on end, making the owner think it has totally disappeared from the tank or is lying dead somewhere in the live rock. But, once it feels comfortable with its new surroundings, it will come out to chase down small scraps of food with the rest of the fish in the tank. Not an aggressive feeder, care should be taken to make sure that it is getting enough food. These fish are resistant to disease and usually can adapt well to aquarium life.


Firefish are omnivores. Along with algae and zooplankton growing in the tank, a firefish goby's diet should include meaty foods, including mysis shrimp, brine shrimp, finely chopped fresh or frozen seafood, and vitamin-enriched prepared foods. Because they have relatively small guts, feed this kind of dartfish twice daily to ensure good nutrition.

Sexual Differences

This species does not seem to have any unique identifying characteristics between the sexes, although females tend to be smaller and thinner.


This is a monogamous species. This fish should be kept solo unless the tank is very large, or in mated pairs. This fish is very timid and will not come out of hiding unless it feels secure. Very little is known about the mating habits of this species, although, most assume its habits are similar to other goby species.