Blackedge spiny eel

Care at a glance

Overview

This is a large, solitary African eel best kept as the only one of its kind, as it defends space against its own species. Give it a long tank with a deep sand floor to burrow in and several pipes or rock caves to claim, because a secure hide by day is what keeps it settled. It ignores robust, mid-water tankmates its own size but will eat small fish, so keep companions large and calm rather than tiny or nippy. Offer meaty foods at dusk: earthworms, prawn pieces, mussel, and frozen bloodworm. Plan on around 400 liters with a firmly weighted cover, since a fish this size finds any loose lid.

In the wild

The blackedge spiny eel lives in West African rivers of the Niger and Volta systems, keeping to shaded margins with cover and current. A soft sand substrate, driftwood, and shady retreats suit it, along with steady, well-oxygenated flow. Aim for warm water around 23 to 28 C and a soft to neutral pH near 6.0 to 7.5, with clean conditions kept up by regular changes, as large eels are heavy feeders that quickly foul stale water.

Good to know

Mastacembelus nigromarginatus is a member of the spiny eel family Mastacembelidae and one of the larger species in the hobby, reaching roughly 50 centimeters. George Boulenger described it in 1898 from West Africa. Like other big Mastacembelus it carries small, deeply embedded scales and a long fringe of dorsal and anal soft rays behind the short spines that name the family, and it has no known captive breeding record.

Did you know

Its name, nigromarginatus, simply means black-margined: a thin dark line runs along the outer edge of the dorsal and anal fins for almost the whole length of the fish, and that trim is the quickest way to tell it from other African eels.

Common questions

Related species

• 

  Marbled spiny eel

  Mastacembelus favus

  Freshwater

  19.7 in (50 cm)119 gal (450 L)75–82°F (24–28°C)

• 

  White-spotted spiny eel

  Mastacembelus alboguttatus

  Freshwater

  19.3 in (49 cm)106 gal (400 L)73–82°F (23–28°C)
• White spot eel

  Mastacembelus unicolor

  Freshwater

  21.7 in (55 cm)119 gal (450 L)73–82°F (23–28°C)

• 

  Eyespot spiny eel

  Mastacembelus notophthalmus

  Freshwater

  17.7 in (45 cm)106 gal (400 L)73–82°F (23–28°C)
• Tin Win's spiny eel

  Mastacembelus tinwini

  Freshwater

  17.7 in (45 cm)106 gal (400 L)73–82°F (23–28°C)

• 

  Liberian spiny eel

  Mastacembelus liberiensis

  Freshwater

  15 in (38 cm)79 gal (300 L)73–82°F (23–28°C)