Peacock Spiny Eel

Care at a glance

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.

Related species

• Zebra spiny eel

  Macrognathus zebrinus

  11.8 in (30 cm)42 gal (160 L)72–81°F (22–27°C)
• Lesser spiny eel

  Macrognathus aculeatus

  15 in (38 cm)85 gal (320 L)73–82°F (23–28°C)

• 

  Half-banded spiny eel

  Macrognathus circumcinctus

  7.9 in (20 cm)57 gal (215 L)75–81°F (24–27°C)
• Marbled spiny eel

  Mastacembelus favus

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

• 

  Tire-track eel

  Mastacembelus armatus

  27.6 in (70 cm)119 gal (450 L)75–82°F (24–28°C)

• 

  Fire eel

  Mastacembelus erythrotaenia

  39.4 in (100 cm)132 gal (500 L)75–82°F (24–28°C)