Purple firefish (Nemateleotris decora) are beautiful marine fish from the Indo-Pacific. They belong to the the family Microdesmidae, which are a group of fishes known as dartfishes. Dartfish are closely related to gobies.
The purple firefish is also known as the elegant firefish, flame firefish, firefish goby, and purple dartfish. They are very colorful fish, but their color and pattern varies from fish to fish.
It is a small fish that only reaches a size of 3.5 inches (9 cm). It should not be kept with large or aggressive species. You must provide lots of rock and loose coral rubble as a substrate so that it has a lot of hiding places. If it doesn't have adequate hiding places and if you keep it with aggressive fish it will refuse to eat and starve to death.
You can keep the purple firefish in a reef tank. In fact, in its natural habitat it hovers above the reef in search of zooplankton on which it feeds. In the aquarium it will eat brine shrimp and frozen meaty chopped foods for marine fish and frozen zooplankton. It will occasionally accept flakes or dry food. You must feed it a variety of foods to prevent malnutrition. If it becomes malnourished its colors will fade.
In general, purple firefish don't get along well with members of their own species. Sometimes you can keep a male and female together and they will get along fine.
They often jump out of the tank when frightened and so you should keep your aquarium covered.
Purple firefish cost about 25-30 dollars each.