Peacock spiny eel

Macrognathus siamensis

Also known as Spotfinned spiny eel, Peacock Eel

FreshwaterFish

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
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 that stays hidden in soft sand through the day and emerges after dark to forage. Give it a deep bed of fine sand it can dig into, since sharp substrate injures its skin, along with caves and wood for cover. It is mostly peaceful but will eat small fish and shrimp, so choose calm tankmates too large to be swallowed. Keep it singly and feed live and frozen foods such as bloodworms, blackworms, and shrimp in the evening. It escapes readily, so fit a tight lid. Give it a tank of at least 265 liters.

In the wild

Macrognathus siamensis is native to Southeast Asia, in the slow, weedy rivers, canals, and floodplains of Thailand and the surrounding region, where the bottom is soft and cover is dense. Recreate this with a deep sand bed, driftwood, hardy plants, and gentle flow, kept dimly lit to suit its nocturnal habits. Keep the temperature between 24 and 28 degrees Celsius and the pH slightly acidic to neutral, from about 6 to 7.5.

Good to know

The peacock spiny eel belongs to Mastacembelidae and grows to about 30 centimeters. It is named for the row of eyespots, usually three to six dark ocelli ringed with pale color, set along the base of its rear dorsal fin. Like its relatives it has a long body, small defensive spines before the dorsal fin, and a fleshy snout for probing the substrate. Aquarium breeding is seldom documented.

Did you know

The peacock spiny eel is named for the row of eye-like spots along the back of its dorsal fin. These false eyes are thought to draw a predator's strike away from the real head at the other end.

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.

How big does a Peacock spiny eel get?

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

Related species