Longfin Barb (Dawkinsia arulius (syn. Puntius arulius; sometimes sold as Barbus arulius)) — 3,5-4,5cm

Overview

Longfin Barb (Dawkinsia arulius) is a lively, attractive schooling barb native to southwestern India, especially the Western Ghats region. Renowned for its flowing fins, bold personality, and constant movement, this species is a popular choice for the spacious community aquarium. Now available for sale UK from Tropical Fish Co, the Longfin Barb brings energy, color, and active shoaling behavior to any well-maintained tropical setup.

Appearance

The Longfin Barb typically reaches around 10 cm in total length, making it a medium-sized member of the barb family. The body is elongated and silvery, marked with vertical bars or patches of darker pigmentation. The most striking feature is the elongated dorsal fin, which in mature males can develop into a long, flowing extension tipped with black. The fins may also show red or orange highlights, especially during breeding displays. Females are generally more robust and less colorful, with shorter fins. Healthy specimens have bright, clear eyes and smooth, undamaged scales.

Natural Habitat

In the wild, Dawkinsia arulius inhabits clear, fast-flowing rivers and streams in the Western Ghats of southwestern India. These waters are well-oxygenated, with rocky or gravelly substrates and moderate to strong currents. The surrounding landscape is lush and forested, providing shade and contributing leaf litter and organic matter to the water. During the monsoon season, water levels rise and flow increases, and the fish move into flooded areas to spawn among submerged vegetation.

Aquarium Setup

A spacious aquarium of at least 150 litres is recommended for a shoal of Longfin Barbs, as they are active swimmers and require plenty of open space. Use a fine gravel or sand substrate and incorporate smooth rocks, driftwood, and robust live plants such as Vallisneria, Java fern, or Anubias to provide cover and visual interest. Ensure good filtration and moderate water movement to replicate the well-oxygenated rivers of their natural habitat. A secure lid is essential, as active barbs can jump when startled or during courtship displays.

Feeding

The Longfin Barb is an omnivore and thrives on a varied diet. Offer quality flakes or small pellets as a staple, supplemented with frozen or live foods such as bloodworms, daphnia, and brine shrimp. Occasional vegetable matter, such as blanched spinach or spirulina-based foods, will support digestive health and color. Feed twice daily in small amounts to maintain excellent water quality and prevent overfeeding. A varied, balanced diet will enhance coloration and support breeding condition.

Behaviour

This barb is lively, active, and social, constantly on the move and best kept in a shoal of at least six individuals. When kept in proper numbers, the Longfin Barb is peaceful and confident, displaying natural schooling behavior and engaging in playful interactions. Lone fish or those kept in undersized groups may become stressed or nippy. Males may engage in mild territorial displays during spawning, but serious aggression is rare. They occupy the middle and upper levels of the aquarium and are most active during feeding time.

Tank Mates

The Longfin Barb is suitable for a community aquarium with other active, medium-sized fish. Good tankmates include other active barbs, danios, rainbowfish, loaches, and catfish such as Corydoras or similar peaceful bottom dwellers. Avoid slow-moving fish with long fins, very small fish that may be bullied or eaten, shrimp and tiny invertebrates, and highly territorial or aggressive species. The constant activity and occasional fin-nipping tendencies of barbs mean they are not suitable for delicate or slow-moving tankmates.

Breeding

Breeding the Longfin Barb in captivity is achievable with careful preparation. Set up a separate spawning tank with fine-leaved plants or spawning mops, and condition adults with rich live and frozen foods. Eggs are scattered among plants, and parents should be removed after spawning to prevent them from eating the eggs. Fry are tiny and require infusoria or liquid fry food initially, graduating to baby brine shrimp as they grow. Maintain soft, clean water and stable temperatures throughout the breeding process.

Why Buy from Tropical Fish Co

Tropical Fish Co is a leading UK aquatics specialist offering healthy, carefully selected barbs direct to your door. Every fish is quarantined, inspected, and dispatched with expert care to ensure it arrives in peak condition. With decades of experience, transparent pricing, and exceptional customer support, we make it easy to add active, attractive species like the Longfin Barb to your collection. Whether you're setting up your first community aquarium or expanding an established setup, our knowledgeable team is here to help you succeed. Order online today and enjoy fast, reliable delivery across the UK.