TankBud

Half-banded spiny eel

Macrognathus circumcinctus

Also known as Zig Zag Eel, Striped-belly spiny eel, Taeniagaster spiny eel, Macrognathus taeniagaster

FreshwaterFish

Half-banded spiny eel (Macrognathus circumcinctus)
The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature
75–81°F
24–27°C
pH
6.0–7.5
Adult size
7.9 in
20 cm
Minimum tank
57 gal
215 L
Temperament
Mostly peaceful
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Difficulty
Medium
Breeding
No record
Rarity
Very rare
Family
Mastacembelidae
Origin
Sumatra, Malaysia, Thailand

Overview

This small spiny eel is a secretive, night-active fish that spends the day buried in the sand with only its snout showing. It must have a soft sand bed it can burrow into, since sharp gravel scratches its scaleless skin and invites infection. Keep it singly with calm tankmates that are too big to be swallowed but not aggressive enough to bully it. Feed live and frozen foods such as bloodworms, blackworms, and small shrimp after dark. It can slip through small gaps, so fit a tight lid. Give it a tank of at least 215 liters.

In the wild

Macrognathus circumcinctus comes from Southeast Asia, in the slow rivers, floodplains, canals, and vegetated margins of Sumatra, Malaysia, and Thailand, where the bottom is soft mud or sand and cover is plentiful. Recreate this with a deep bed of fine sand, gentle flow, and hiding places among wood and plants. Keep the temperature between 24 and 27 degrees Celsius and the pH slightly acidic to neutral, from about 6 to 7.5.

Good to know

The half-banded spiny eel belongs to Mastacembelidae, the spiny eel family, and reaches about 20 centimeters, staying smaller in most aquariums. It is named for the row of dark bars that reach only halfway down its flanks, and for the small spines set ahead of its dorsal fin. Like other spiny eels it has a long, flexible body and a fleshy, trunk-like snout it uses to probe the substrate. Breeding in home aquariums is rarely recorded.

Did you know

The half-banded spiny eel burrows into soft sand and rests through the day with just its snout poking out. A tank with sharp gravel instead of sand can scrape its bare skin and lead to serious infections.

Common questions

What size tank does a Half-banded spiny eel need?

A Half-banded spiny eel needs at least 57 gal (215 L). It spends most of its time in the bottom.

What temperature and pH does a Half-banded spiny eel need?

A Half-banded spiny eel is comfortable at 75–81°F (24–27°C) with a pH of 6.0–7.5.

How big does a Half-banded spiny eel get?

An adult Half-banded spiny eel reaches about 7.9 in (20 cm).

Related species