Lesser spiny eel
Macrognathus aculeatus
Care at a glance
- Temperature
- 73–82°F (23–28°C)
- pH
- 6.0–7.5
- Adult size
- 15 in (38 cm)
- Minimum tank
- 85 gal (320 L)
- Temperament
- Mostly peaceful
- Social behavior
- Solitary
- Swim level
- Bottom
- Difficulty
- Medium
- Breeding
- No record
- Rarity
- Very rare
- Origin
- Thailand, Laos, Cambodia, Vietnam
- Family
- Mastacembelidae
Overview
The lesser spiny eel is a night-active burrower that hides in soft sand by day and comes out after dark to hunt along the bottom. It needs a deep bed of fine sand it can bury into, as coarse gravel damages its delicate skin. Though generally peaceful, it will eat small fish and shrimp it can swallow, so give it larger, calm tankmates. Keep it singly, feeding live and frozen foods such as earthworms, bloodworms, and shrimp in the evening. It is a determined escape artist, so seal the lid. This eel grows fairly large and needs a tank of at least 320 liters.
In the wild
Macrognathus aculeatus comes from Southeast Asia, in the slow rivers, lakes, and flooded lowlands of Thailand, Laos, Cambodia, and Vietnam, where soft substrate and submerged cover are common. Recreate its home with a deep, soft sand bed, driftwood and plants for shelter, and gentle, well-filtered flow. Keep the temperature between 23 and 28 degrees Celsius and the pH slightly acidic to neutral, from about 6 to 7.5.
Good to know
The lesser spiny eel belongs to Mastacembelidae, the spiny eel family, and reaches around 38 centimeters. Its long, snake-like body carries a row of short, sharp spines in front of the soft dorsal fin, which give the family its name, and it ends in a small, pointed, trunk-like snout. Spiny eels are not true eels but bony fish with a very elongated shape. Breeding is rarely recorded in home aquariums.
Did you know
Despite the name, the lesser spiny eel is not a true eel at all. It is a bony fish with a stretched-out body and a row of short defensive spines along its back, set just ahead of the soft fin.
Where to buy
Some links may not be the exact species or variety.
- Dan's Fish Freshwater fish, shrimp and snails with a live arrival guarantee
- The Wet Spot Tropical Fish Large freshwater selection from a longtime Portland fish store
…or ask your local fish store.
Appears in
Keeping Lesser spiny eel?
Track water tests, reminders and stocking fit.
Related species

Peacock Spiny Eel
Macrognathus siamensis11.8 in (30 cm)70 gal (265 L)75–82°F (24–28°C)Zebra spiny eel
Macrognathus zebrinus11.8 in (30 cm)42 gal (160 L)72–81°F (22–27°C)
Half-banded spiny eel
Macrognathus circumcinctus7.9 in (20 cm)57 gal (215 L)75–81°F (24–27°C)Marbled spiny eel
Mastacembelus favus19.7 in (50 cm)119 gal (450 L)75–82°F (24–28°C)
Tire-track eel
Mastacembelus armatus27.6 in (70 cm)119 gal (450 L)75–82°F (24–28°C)
Fire eel
Mastacembelus erythrotaenia39.4 in (100 cm)132 gal (500 L)75–82°F (24–28°C)