Longfin Rosy Barb (Pethia conchonius var.)

The Longfin Rosy Barb is a selectively bred variety of Pethia conchonius (the Rosy Barb) developed for greatly extended fin rays — particularly the dorsal, caudal, and pelvic fins — that create dramatic flowing extensions across all fins. This longfin form retains the full hardiness, ease of care, and peaceful schooling nature of the standard Rosy Barb.

The Rosy Barb is native to hill streams and rivers in northern India, Bangladesh, and neighboring South Asian countries, where it inhabits clear, moderately flowing water. Males develop vivid rose-red to bright red body coloration during breeding season — particularly intense in longfin males in breeding condition — while females remain olive-green to silver with a rounded body profile.

Reaching 8–10 cm, Rosy Barbs are among the larger community barb species. They are active, vigorous schooling fish that appreciate moderate current and well-oxygenated water. Their subtropical origins mean they tolerate cooler temperatures well — an advantage in unheated or lightly heated indoor tanks.

Rosy Barbs are occasionally nippy with very long-finned or slow-moving species. Ironically, the Longfin variety — with its own extended fins — may be slightly less likely to fin-nip due to having striking fins of its own, though this is not guaranteed.

Longfin Rosy Barbs are very adaptable: pH 6.5–7.5, hardness 5–20 dGH, and temperatures 15–22°C. They prefer cooler conditions than most tropical fish, making them suitable for unheated indoor aquariums in temperate climates. Sustained temperatures above 24°C may cause stress over time.

A minimum 100-liter aquarium is recommended for a group of 6–8. They need significant horizontal swimming space and moderate current. Dense plantings around the tank perimeter with open central space suits them well. A robust, tight-fitting lid is important as they may jump.

Feed a varied omnivorous diet: quality flake food, pellets, vegetable-based flakes, blanched vegetables, daphnia, brine shrimp, and bloodworms. Including plant-based foods prevents nibbling on aquatic plants.

Compatible with other barbs, danios, corydoras, medium tetras, and larger livebearers. Avoid housing with very long-finned, slow species (fancy guppies, bettas, angelfish with very long fins) as fin-nipping can still occur. The longfin variety's own extended fins may be targeted by nippy tankmates.

Keep in groups of at least 6 for natural schooling behavior and to reduce fin-nipping through distributing the behavior. Water changes of 25–30% weekly maintain water quality.