The Purple Firefish (Nemateleotris decora) is also known by various common names such as the Decorated Firefish and even the Fire Goby. The colors on this fish are simply amazing. Purple Firefish have a white or yellow body that fades to black towards a multi-colored caudal fin, and a purple face along with red/orange fins lined in streaks of black. This fish likes to hover in the water column just outside it’s hang out or over the sandy substrate. While hovering they flick their dorsal and pectoral fins in unison, perhaps for stability. This firefish is considered a very good if not great beginner’s fish because they are very hardy, should eat most fish foods offered, and should remain disease free if kept in optimal conditions. Just because they are listed as a “hardy” fish, doesn’t mean that they can’t or won’t come down with a disease. Quarantine ALL new arrivals.
The Purple Firefish only gets to be about 3.5 to 4 inches when fully grown and can be kept in saltwater nano tanks as small as 10 gallons. Obviously, with a small tank you need to be extra diligent with your water quality. Behavior wise, they should do well with most species of similar size and temperament. If you’re planning on keeping them in multiples, you may have issues. Some say it can be done (in very large setups) others say you should only keep one per tank. According to Scott Michael, “they (N. decora) are the most aggressive of the firefishes, it should be housed singly or in male-female pairs”. Determining gender is very difficult if at all possible. Be on the safe side and only stock one per tank. Also, given their size, you don’t want to keep them in tanks with Triggers, Lionfish, etc.You should also know that they are accomplished tank jumpers. Having an open top tank may not work out for you with this species. A fitted aquarium hood with limited escape points is a necessity. Live rock or other suitable items that can provide shelter for the Purple Firefish are also needed. These hiding places may help them acclimate quicker and lessen the chances of tank jumping.
Feeding them shouldn’t be much of a problem. This firefish should accept fresh or frozen (thawed) marine fish foods, live foods (brine shrimp, mysids) and even flake foods. If you’re having difficulty getting them to eat, check your water parameters and try a variety of foods until they start eating. You may notice a behavior that looks like they are biting at the water. This is how they eat, picking at swimming zooplankton in the water column.