TankBud

Peacock spiny eel

Macrognathus siamensis

Also known as Spotfinned spiny eel, Peacock Eel

FreshwaterFish

Peacock spiny eel (Macrognathus siamensis)
Florida Museum · CC BY 4.0

Care at a glance

Temperature
75–82°F
24–28°C
pH
6.0–7.5
Adult size
11.8 in
30 cm
Minimum tank
70 gal
265 L
Temperament
Mostly peaceful
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Medium
Breeding
No record
Rarity
Very rare
Family
Mastacembelidae
Origin
Sumatra, Malaysia, Thailand

Overview

The peacock spiny eel is a night-active, burrowing fish for the bottom of a large tank. It suits a keeper with a little experience.

Did you know

The peacock spiny eel is named for the row of eyespots along the base of its rear dorsal fin. There are usually three to six, each a dark spot ringed with pale color. These false eyes are thought to draw a predator's strike away from the real head at the other end.

Caring for the peacock spiny eel

Keep the peacock spiny eel in a tank of 70 gal (265 L) or larger, with a tight lid, since it escapes readily. Give it a deep bed of fine sand to dig into, because sharp substrate injures its skin. Add caves, driftwood and hardy plants for cover, and keep the light dim and the flow gentle.

Keep the water slightly acidic to neutral, at 75 to 82°F (24 to 28°C) and a pH of 6.0 to 7.5. It stays hidden in the sand through the day and comes out after dark to forage. Feed live and frozen foods in the evening, such as bloodworms, blackworms and shrimp.

Keep it singly. The peacock spiny eel is mostly peaceful, but it will eat small fish and shrimp. Choose calm tank mates too large to be swallowed. Aquarium breeding is seldom documented.

Good to know

Macrognathus siamensis belongs to the spiny eel family, Mastacembelidae. Like its relatives, it has a long body, small defensive spines before the dorsal fin and a fleshy snout for probing the substrate. It also goes by the name spotfinned spiny eel.

In the wild

The peacock spiny eel is native to Southeast Asia, including Sumatra, Malaysia and Thailand. It lives in slow, weedy rivers, canals and floodplains, where the bottom is soft and cover is dense.

Common questions

What size tank does a peacock spiny eel need?

A peacock spiny eel needs at least 70 gal (265 L). It spends most of its time in the bottom.

What temperature and pH does a peacock spiny eel need?

A peacock spiny eel is comfortable at 75–82°F (24–28°C) with a pH of 6.0–7.5.

What does a peacock spiny eel eat?

A peacock spiny eel eats live and frozen foods such as bloodworms, blackworms and shrimp. Feed it in the evening, as it forages after dark.

How big does a peacock spiny eel get?

An adult peacock spiny eel reaches about 11.8 in (30 cm).

Related species