Long Fin Rosy Barb (Pethia conchonius)

Common Name

Long Fin Rosy Barb

Origin and Habitat

The wild species ranges across the Ganges and Brahmaputra drainages in India, Nepal, and Bangladesh, with populations also introduced in other parts of Asia. It inhabits clear to slightly turbid streams, irrigation canals, and quiet pools with sand or fine gravel, scattered stones, and patches of water plants. Seasonal changes bring cooler water and higher flow after rains, while dry periods leave warm, slower reaches with thick biofilm and algae to graze.

Temperature and Water Conditions

Preferred temperature is 70 to 78 F, which is 21 to 26 C. Wild waters are often near neutral, commonly in the 6.0 to 7.5 pH range, with moderate oxygen and gentle to moderate current. In aquaria, stable conditions matter more than chasing exact numbers, except when you follow a specific breeding plan. Keep water clean with steady filtration, good surface movement, and regular partial changes.

Appearance and Size

Longfin lines are bred for saturated red to ember orange color that looks like it glows under good lighting. Males show the most fire, especially when competing or courting, and long flowing fins add a graceful banner effect in the current. Females are fuller bodied with a softer gold to rose tone. Adults commonly reach about 8 to 10 cm, roughly 3 to 4 inches, with exceptional old males sometimes larger.

Diet in the Wild

An omnivore that grazes algae and biofilm, picks at small crustaceans and insect larvae, and browses tender plant tips when available.

Feeding in Captivity

Use a high quality small pellet or granule as the staple. Rotate in frozen and live foods such as daphnia, cyclops, and baby brine shrimp, and offer greens like blanched spinach, zucchini curls, or spirulina flakes. A varied menu keeps color vivid and growth steady. Two small feedings per day work well for active groups.

Behavior and Tank Setup

An energetic schooling barb that shows its best color and manners in a larger group. Keep at least eight, with twelve or more even better, so attention is spread and displays stay playful rather than pushy. A 29 gallon tank is a good start, larger tanks bring out gorgeous group movement. Use sand or fine gravel, rounded stones, and open lanes for swimming, with hardy plants or faux stems along the back. Flow should be gentle to moderate with high oxygen.

Good companions include active midwater fish of similar size, fast tetras, rainbowfish, white cloud minnows in cooler setups, and bottom friends like Corydoras and small plecos. Avoid slow, long fin species that might be teased by an excited shoal.

Breeding

Conditioning: Separate males and females for a week and feed well with small live and frozen foods. Cooler water changes can help simulate seasonal cues.

Spawning setup: Use a separate tank with fine leaf plants or mops, or a mesh or marble layer that allows eggs to fall out of reach. A ratio of two males to one female often yields good fertilization. Many hobbyists see activity at dawn after dim pre lights.

Eggs and fry: Adults do not guard the spawn and will eat eggs, so remove parents right after spawning. Eggs typically hatch in a couple of days at 74 to 76 F. Fry need infusoria or a commercial liquid starter at first, then move to newly hatched brine shrimp and a fine powdered fry food. Keep water stable and very clean with gentle air driven filtration and small daily changes.

Quick Facts

• Scientific name: Pethia conchonius
• Common name: Long Fin Rosy Barb
• Origin: Ganges and Brahmaputra drainages, South Asia, with introduced populations elsewhere
• Adult size: about 8 to 10 cm, roughly 3 to 4 inches
• Temperature: 70 to 78 F preferred, 21 to 26 C
• Wild pH: commonly 6.0 to 7.5, stability in captivity is most important
• Temperament: active, social, best in larger groups
• Diet: omnivore, accepts quality prepared foods with plant and protein variety
• Breeding type: egg scattering among plants or mops, no parental care

Tropical Fish Co. Notes

Under the right light these look like moving embers, they really glow. Give a lively group room to swim, steady flow, and strong filtration, and the color and motion will stand out even across a crowded fish room.