Cyprinids (Cyprinidae)

Filament Barb

Dawkinsia filamentosa

A member of the Cyprinidae family, known as the Filament Barb (scientific name Dawkinsia filamentosa), is an active schooling fish. Its compatibility with many popular aquarium species makes it attractive to enthusiasts. This fish is easy to care for and breed, making it suitable even for beginner aquarists.

Tank
from 243 L (64 gal), 250 L (66 gal) recommended
Temperature
20 – 25 °C (68 – 77 °F)
Size in aquarium
12 cm (4.7 in)
Acidity
pH 6–7
Natural rangeRange on the map
  • Western Ghats area
  • Kerala area
  • India

Tank conditions

Plan the tank stocking
Temperature
20 – 25 °C (68 – 77 °F)
Water pH
Slightly acidic (6) – Neutral (7)
Water dH
Very soft (3) – Hard (15)
Water salinity
very low (up to ~3 g/L)
Size in aquarium
12 cm (4.7 in)
Lifespan
8 years
Temperament
Peaceful, active/mobile
Toward small fish
not a predator
Required aquarium volume
from 243 L (64 gal), 250 L (66 gal) recommended
Lighting
dimmed
Substrate
rocky rock formations, boulders, etc.
Water flow
weak
Swimming level
middle level
Feeding
Any (universal)
Keeping
Schooling usually from 5–6 individuals and more
Jumping
high a tight-fitting lid is essential
  • Lifespan. A lifespan to expect under good care, not a measured value: it depends heavily on tank volume, water quality and diet — and for selectively bred forms, on their origin as well.
  • Toward small fish. Based on the Predators category in the catalog or the temperament in the species parameters. “A risk to small fish” means the species is not a predator by habit, yet will swallow any fish that fits in its mouth.
  • Required aquarium volume. The 243 L minimum corresponds to a tank footprint of 120×45 см. The recommended 250 L is for the group size given under keeping mode.

Care and keeping

Description

These cyprinids reach significant sizes: adults grow to approximately 12 cm in length. Males are usually smaller than females, but their coloration is more vibrant, and the dorsal fin has unusual features — its rays in adult males become greatly elongated, resembling filaments. During spawning, small tuberculate growths appear on the males' heads, around the mouth. The fish's body has a silvery coloration with a noticeable dark spot at the base of the tail, the tips of which are often adorned with a red stripe.

Habitat

The natural habitat of this species is limited to the southern tip of the Indian subcontinent. The fish is found along the Western Ghats mountain range, located in the modern Indian states of Kerala, Tamil Nadu, and Karnataka. They most often inhabit shallow lowland river floodplains and marshy coastal areas, where brackish seawater often penetrates.

Behavior and Compatibility

This species is schooling, preferring to stay in groups of 8 to 10 individuals. The fish are highly active, but their activity is mainly directed at their conspecifics, so the barb will not bother other aquarium inhabitants. It is friendly towards other fish of similar size and temperament. However, despite its peaceful nature, it is not recommended to keep it with very small fish, as they may be perceived as food.

Care and Maintenance

For a small school of these fish, a tank of at least 250 liters will be sufficient. The aquarium can be decorated with stones and boulders, sand as a substrate, and several snags, roots, or tree branches to create shelters. In addition, groups of undemanding plants such as mosses, ferns, and Anubias will be well-suited. For the Filament Barb, water quality is extremely important, as it cannot tolerate organic and other waste pollution. Special attention should be paid to an effective filtration system and regular water changes, which should be performed at least once a week, replacing 30–50% of the aquarium volume. Another important aspect is a high level of dissolved oxygen. For this, it is recommended to use several air stones placed in different parts of the tank. Although the fish can live in brackish water in nature, brackish water is not required in aquarium conditions if the fish has not previously been kept in such conditions. A freshwater aquarium will be the best choice.

Diet

This omnivorous species readily accepts a variety of foods: dry, frozen, and live. It is important to provide a balanced diet, which may include flakes or pellets in combination with bloodworms, daphnia, and small worms, available in both live and frozen forms. Feed 2–3 times a day, offering portions that the fish consume within 5 minutes, and any leftover food should be promptly removed.

Breeding and Reproduction

Barbs are egg-laying species. In a home aquarium, spawning can occur at any time of the year. Females lay eggs in the water, and males fertilize them; after this, the eggs are left without parental care. Since parental instincts in barbs are poorly developed, they can eat their eggs immediately after spawning. If the goal is to preserve the offspring, then breeding should be carried out in a separate spawning tank. For this, coarse substrate is used, such as pebbles or decorative glass marbles, with sufficient gaps between particles. The eggs fall into these gaps, becoming inaccessible for consumption. As additional protection, a fine mesh can be placed over the substrate. Any plants are acceptable, and additional decoration is generally not required. Equipment needed includes a heater, an aerator, a low-power lamp, and a simple sponge filter. The aquarium is filled with water from the main tank. The period of courtship begins when the females become noticeably rounded, and characteristic light tubercles appear on the males' heads. At this point, the females and one or two of the strongest males are transferred to the spawning tank. After spawning, the fish are returned. Fry appear after 24–28 hours and begin to swim freely after approximately one day. It is recommended to feed them specialized micro-food, which can be purchased at pet stores.

Diseases

A balanced aquarium ecosystem, providing suitable conditions for the species and proper nutrition, is the best prevention for various diseases. Most often, diseases arise as a consequence of unsatisfactory environmental conditions, and this is what should be addressed first. However, knowing treatment methods and symptoms of common ailments is also useful.

How to choose

When choosing Filament Barbs, it is important to assess the overall activity of the school in the aquarium. Healthy individuals should be mobile, constantly moving, and show interest in food. Avoid fish with signs of lethargy, scale damage, or unnatural behavior, such as prolonged hovering at the surface or bottom. Carefully inspect the condition of the fins and skin. In healthy fish, the fins should be spread out, without signs of rot, white growths, or ulcers. The coloration should correspond to the age: in young individuals, it is usually less intense, with clear dark stripes, while adult fish exhibit a characteristic silvery sheen and a dark spot at the base of the tail. Do not confuse the natural breeding tubercles on the heads of males with signs of disease. — Choose individuals from aquariums where no dead or obviously sick fish are observed. — Pay attention to plumpness: a sunken abdomen may indicate emaciation or internal parasitic infections. — Keep in mind that this species is schooling, so it is recommended to acquire a group of 6–8 individuals to reduce stress levels during relocation.

Compatibility

There are no pair reviews for this species yet — check tankmates in the matcher.

All tankmates

Plants and this fish

Matching water does not mean the plant will stay intact.

Frequently asked questions

The essentials: size, tank volume, water parameters and care

How big does Filament Barb get?

An adult reaches 12 cm in length. Plan the tank around the maximum size: the fish quickly outgrows a cramped setup.

What size aquarium does Filament Barb need?

The recommended volume is 250 L. A smaller tank speeds up nitrate build-up and raises stress levels.

What water parameters does Filament Barb need?

Temperature 20–25 °C, pH 6–7, hardness 3–15 dGH. Stability matters more than exact values: sudden swings are harder on the fish than a small deviation from the ideal.

How long does Filament Barb live?

Around 8 years when kept properly. Lifespan depends directly on tank volume, water quality and a varied diet.

Is Filament Barb aggressive?

Temperament: peaceful, active/mobile. Keep this in mind when choosing tank mates.

How many Filament Barb should be kept together?

Recommended setup: schooling (usually from 5–6 individuals and more). Ignoring this is a common cause of stress and disease.

What does Filament Barb eat?

Diet type: any (universal). Feed small portions that are finished within a couple of minutes — overfeeding does more harm than underfeeding.

What is the scientific name of Filament Barb?

The scientific name of the species is Dawkinsia filamentosa, family Cyprinids (Cyprinidae). It also appears in the literature as: Barbus filamentosa, Leuciscus filamentosus, Puntius filamentosus.

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Other scientific names and conservation status

Other scientific names
Barbus filamentosa, Leuciscus filamentosus, Puntius filamentosus, Systomus filamentosus, Systomus maderaspatensis, Systomus madraspatensis
Categories
Cyprinids
Conservation status
Least concernLC