TankBud

Multifilis threadfin

Polynemus multifilis

Also known as Paradise threadfin (multifilis), Elegant threadfin

FreshwaterFish

Multifilis threadfin (Polynemus multifilis)

Care at a glance

Temperature
75–84°F
24–29°C
pH
6.5–7.5
Adult size
11 in
28 cm
Minimum tank
159 gal
600 L
Temperament
Peaceful
Social behavior
Social
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Difficult
Breeding
Medium
Rarity
Rare
Family
Polynemidae
Origin
Large rivers of Indochina, Sumatra, and Borneo

Overview

The Multifilis threadfin is a large, demanding fish for the bottom of a big, open tank. It is for experienced keepers.

Did you know

The Multifilis threadfin feels its way along the riverbed with a fan of thread-like fin rays. It tastes and touches the mud for hidden food. The filaments work like extra fingers, letting it hunt in water too murky to see through.

Caring for the Multifilis threadfin

The Multifilis threadfin needs a big tank of at least 159 gal (600 L), with open floor space rather than a cluttered aquascape. Its long pectoral filaments trail along the substrate and are delicate sensory organs. Keep the layout smooth, with soft, fine sand and rounded wood, and avoid sharp rock.

Keep the water warm and clean, at 75 to 84°F (24 to 29°C) with a pH of 6.5 to 7.5. Feed meaty sinking foods such as bloodworm, prawn and small pieces of fish.

This threadfin is peaceful and sociable, and it is happier in a small group than alone. Treat tank mates with caution, and pick calm fish of similar size that will not nip its filaments or bully it. Breeding it is of moderate difficulty, though it is little documented in aquaria. This large river fish is rarely spawned in captivity.

Good to know

Polynemus multifilis belongs to Polynemidae, the threadfins. Each pectoral fin is split into roughly fourteen long, free filaments that move independently. Together they form a bank of trailing sensors that it uses to find food.

In the wild

The Multifilis threadfin lives in large, turbid lowland rivers of Indochina, Sumatra and Borneo. It moves over sandy and muddy bottoms where visibility is poor.

Common questions

What size tank does a Multifilis threadfin need?

A Multifilis threadfin needs at least 159 gal (600 L). It spends most of its time in the bottom.

What temperature and pH does a Multifilis threadfin need?

A Multifilis threadfin is comfortable at 75–84°F (24–29°C) with a pH of 6.5–7.5.

What does a Multifilis threadfin eat?

A Multifilis threadfin eats meaty sinking foods such as bloodworm, prawn and small pieces of fish.

How big does a Multifilis threadfin get?

An adult Multifilis threadfin reaches about 11 in (28 cm).

Related species