News / Species Spotlight / Species Spotlight - Black-edge Moray (Gymnothorax nigromarginatus) (10/11/17)

Species Spotlight - Black-edge Moray (Gymnothorax nigromarginatus)

Species Spotlight - Black-edge Moray (Gymnothorax nigromarginatus)
Gymnothorax is the most diverse group of moray eel in the West Atlantic, with a dozen species. However, most of these are rarely seen in aquariums. For many, this is because they typically occur in deeper reef environments, while others simply grow too large to be practical for the average fish tank. By far the most popular member of the genus is the Goldentail Moray Eel (G. miliaris), a small species found in shallow reef habitats and which occasionally occurs in a bright yellow morph known as the Banana Moray.

But there are other delights to be found among the Atlantic Gymnothorax. The Blackedge Moray (G. nigromarginatus) is one of the nicer options. Its body is a creamy grey, with many small pale spots scattered about its back, and accenting all of this is a dark edge running along the entirety of the dorsal and anal fins. Its beauty is subtle, but substantial. Whereas the Banana Moray hits you with color, the Blackedge Moray arrives with style and grace.

In the wild, youll find this fish in reasonably shallow waters, typically from 10-20 meters, but sometimes deeper. Sources disagree on the preferred habitat (if there even is one), with some suggesting this to be a species associated more with soft bottoms and sea grasses, while others mention it occurring along rocky reefs, but never in association with corals.

Fully grown, G. nigromarginatus reaches fairly modest proportions, topping out at around three feet in length. This will necessitate a large aquarium, somewhere in excess of 100 gallons being ideal, as well as some robust filtration to handle the waste produced by so much piscine biomass, but it pales in comparison to what is required for keeping some of the true giants in this genus, like the Green Moray (G. funebris), a species capable of growing to twice the size of its blackedged cousin.

Gymnothorax typically feed upon fishes, having row upon row of razor sharp teeth to accommodate this diet. Aquarium specimens will learn to accept whole or chopped frozen fishes and should be provided with a diverse menu, so as to avoid any potential nutrient deficiencies. Obviously, tankmates must be chosen with care and must be large enough to avoid being eaten. Groupers, puffers and lionfishes are some of the better options, as are some of the larger tangs and angelfishes and wrasses. Lastly, always remember to provide a suitable amount of hiding spots when keeping eels, whether with rocks or artificial decoration or even PVC pipes.