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Frecklefin spiny eel

Macrognathus maculatus

Also known as Maculatus spiny eel, Buff back eel

FreshwaterFish

Frecklefin spiny eel (Macrognathus maculatus)

Care at a glance

Temperature
73–82°F
23–28°C
pH
5.5–7.0
Adult size
11 in
28 cm
Minimum tank
66 gal
250 L
Temperament
Mostly peaceful
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Medium
Breeding
No record
Rarity
Rare
Family
Mastacembelidae
Origin
Sundaland rivers, Malaysia and Indonesia

Overview

The frecklefin spiny eel is a mostly peaceful, sand-burrowing eel for a soft-water tank. It takes a little experience to keep well.

Did you know

The frecklefin spiny eel is not a true eel, despite its shape and name. Spiny eels sit in the order Synbranchiformes, alongside the swamp eels. The short spines before the dorsal fin, which real eels lack, mark the family out.

Caring for the frecklefin spiny eel

Give the frecklefin spiny eel at least 66 gal (250 L), with fine sand and a close-fitting lid. It buries in sand by day and patrols the floor and glass line after dark, so soft sand and shaded hides come first. Add driftwood, dried leaves and subdued light, with plenty of low cover to retreat into.

Keep the water soft, at 73 to 82°F (23 to 28°C) with a pH of 5.5 to 7.0, and the flow gentle. Feed meaty foods such as frozen bloodworm, blackworm, chopped earthworm and small prawn pieces. Drop them near the substrate at dusk.

Keep it on its own, since it lives alone in the wild and tolerates its own kind poorly in a tank. It is gentle with tank mates it cannot swallow but will eat small fish. Pair it with calm, medium-sized species, and avoid tiny or nervous ones. Like most of the family, it has no documented aquarium breeding record.

Good to know

The frecklefin spiny eel, Macrognathus maculatus, belongs to the family Mastacembelidae. The name maculatus means spotted, for the freckling scattered along its fins and flanks. In the wild it feeds on insect larvae, worms and small crustaceans, lifted from the substrate with its mobile snout. It is also called the maculatus spiny eel or buff back eel.

In the wild

The frecklefin spiny eel lives in shaded lowland forest streams across Sundaland, in Malaysia and Indonesia. The water there is soft and acidic under a leafy canopy, with beds of litter and submerged plants.

Common questions

What size tank does a frecklefin spiny eel need?

A frecklefin spiny eel needs at least 66 gal (250 L). It spends most of its time in the bottom.

What temperature and pH does a frecklefin spiny eel need?

A frecklefin spiny eel is comfortable at 73–82°F (23–28°C) with a pH of 5.5–7.0.

What does a frecklefin spiny eel eat?

A frecklefin spiny eel eats meaty foods such as frozen bloodworm, blackworm, chopped earthworm and small prawn pieces. Drop them near the substrate at dusk.

How big does a frecklefin spiny eel get?

An adult frecklefin spiny eel reaches about 11 in (28 cm).

Related species