Firefish

Nemateleotris magnifica

Also known as Firefish Goby, Fire Dartfish, Magnificent Dartfish, Fire Goby

SaltwaterFish

Firefish (Nemateleotris magnifica) — Rickard Zerpe · CC BY 2.0

Care at a glance

Temperature: 72–81°F (22–27°C)
pH: 8.1–8.4
Adult size: 3.5 in (9 cm)
Minimum tank: 20 gal (75 L)
Temperament: Mostly peaceful
Social behavior: Social
Swim level: Middle
Difficulty: Easy
Breeding: Hard
Rarity: Very common
Reef safe: Reef safe
Origin: Indo-Pacific (East Africa to Hawaii)
Family: Microdesmidae

Overview

Firefish are reef safe and completely trustworthy around corals and invertebrates. They are shy and docile toward other fish, but they can be aggressive toward their own kind, so keep a single fish or a bonded pair rather than several loose individuals in a smaller tank. Their standout trait is that they are champion jumpers that will squeeze through the smallest gap when startled, so a secure lid is not optional. Feed small meaty foods and frozen preparations for carnivores.

In the wild

Firefish hover just above the substrate near the reef, facing into the current to pick plankton out of the water, and each fish keeps a bolt hole in the rock or rubble that it dives into the instant it feels threatened. In the aquarium they want a tank of around 75 liters or more with plenty of rockwork full of crevices, and above all a tight fitting lid. They are dartfish rather than true gobies and stay near the bottom third of the tank until they feel secure, then hold in open water.

Good to know

The tall first dorsal fin flicks up and down almost constantly, which may help firefish signal to each other and judge distances near their burrows. The species is a plankton picker built for hovering rather than resting on the bottom. Spawning has been observed but rearing the tiny pelagic larvae is very difficult, so almost all firefish in the trade are wild collected.

Did you know

When a firefish spooks it collapses that tall dorsal fin and rockets straight into its bolt hole in the rock, and if the tank is not covered that same escape reflex sends it straight out through any gap in the lid instead.