Red Tailed Black Shark

Epalzeorhynchos bicolor

Cyprinids

A striking and highly active bottom-dwelling cyprinid known for its jet-black body and vibrant red tail. While beautiful, they are notoriously territorial, especially toward their own kind, similar-looking species (like Rainbow Sharks), and sometimes other bottom-dwellers. They must be kept as the only 'shark' in the tank and require a large footprint with plenty of caves and broken sightlines.

At a Glance

Adult Size15 cm
Body ShapeFusiform
Growth RateModerate
TemperamentAggressive
Water TypeFreshwater Only
Flow PreferenceModerate
Waste OutputMedium
StockingSolo only

Tank Requirements

Minimum Volume208 L
Minimum Length120 cm
FlowModerate
Water TypeFreshwater Only
Must-Haves in the Tank
Driftwood (Digestion/Hiding)Plants - Densely coveredSmooth Gravel (Sensitive Barbels)

Water Parameters

Temperature2228°C
pH6.57.5
Hardness515 dGH

Temperament & Compatibility

Aggression LevelAggressive
7/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least1 (solo is fine)
Max per Tank1
Can Live Alone?Yes
Behavior Traits
Territorial (Defends specific area)Aggressive to same species/look-alikesHyperactive / Fast SwimmerJumper (Lid Required)

Available Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Standard

The standard and most common variant. Must be kept singly to prevent fatal territorial disputes.

Same care requirements as the base species

Also known as: Wild Type

Red Tailed Black Shark Care Guide Summary

The Red Tailed Black Shark, scientifically known as Epalzeorhynchos bicolor, belongs to the Cyprinids family group. Adults reach a maximum size of approximately 15 cm and have a fusiform body shape with a moderate growth rate. Classified as aggressive, this species primarily occupies the bottom and mid-level zones of the aquarium and produces a medium level of biological waste.

To thrive, the Red Tailed Black Shark requires a freshwater only aquarium with a minimum volume of 208 litres and a tank length of at least 120 cm. Water temperature should be maintained between 22°C and 28°C, with a pH range of 6.57.5 and a general hardness of 515 dGH. A moderate water flow is preferred.

Due to its specialist needs, the Red Tailed Black Shark is best suited for fishkeepers who can provide a carefully planned setup. The Red Tailed Black Shark is typically available in one standard form.

Red Tailed Black Shark Habitat Setup

When setting up an aquarium for the Red Tailed Black Shark, a moderate water flow best suits their natural preferences. Because this species occupies the bottom and mid-level zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include smooth gravel or rounded substrate to protect their sensitive barbels, driftwood, which can serve as both a hiding place and a dietary supplement, and dense planting to provide cover, break sightlines, and reduce stress. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.

Red Tailed Black Shark Compatibility Notes

Classified as aggressive, the Red Tailed Black Shark is best housed alone, as they do not tolerate others of their kind in confined spaces. When choosing tankmates, conspecific aggression can be intense, especially in smaller tanks, territorial behaviour may cause issues if hiding spots or floor space are limited, and their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the bottom and mid-level zones can help reduce competition and territorial overlap.

Frequently Asked Questions About Red Tailed Black Shark

How big does Red Tailed Black Shark get?+
Red Tailed Black Shark (Epalzeorhynchos bicolor) typically reaches a maximum adult size of approximately 15 cm. They have a fusiform body shape and a moderate growth rate.
What tank size does Red Tailed Black Shark need?+
A minimum aquarium volume of 208 litres and a tank length of at least 120 cm are recommended for Red Tailed Black Shark. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Red Tailed Black Shark need?+
Red Tailed Black Shark thrives in freshwater only conditions with a temperature range of 22–28°C, a pH between 6.5 and 7.5, and a general hardness of 5–15 dGH. A moderate water flow is preferred.
Is Red Tailed Black Shark peaceful or aggressive?+
Red Tailed Black Shark is classified as aggressive with an aggression score of 7 out of 10. Careful tankmate selection is essential to avoid conflict.
Can Red Tailed Black Shark live with others of its kind?+
No. Only one Red Tailed Black Shark should be kept per tank. Keeping multiples in the same aquarium typically results in aggression and stress.
Does Red Tailed Black Shark have any special tank requirements?+
Yes. Red Tailed Black Shark benefits from driftwood (digestion/hiding), plants - densely covered, and smooth gravel (sensitive barbels) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Red Tailed Black Shark need a lid on the tank?+
Yes. Red Tailed Black Shark is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.

Similar Species

Rainbow Shark

Epalzeorhynchos frenatum

Cyprinids
15 cm Aggressive

A popular, active freshwater 'shark' (actually a cyprinid) known for its striking red fins contrasting with a dark or albino body. They are highly territorial bottom-dwellers. Only keep one per tank, as they are notoriously aggressive toward their own kind, other 'sharks' (like the Red Tail Shark), and similar-looking bottom feeders.

Bala Shark

Balantiocheilos melanopterus

Cyprinids
35 cm Mostly Peaceful

Despite its name, the Bala Shark is a peaceful, schooling cyprinid. They are extremely active, fast swimmers that grow very large and startle easily. They are notorious for injuring themselves by crashing into the aquarium glass if kept in small tanks or easily spooked. They must be kept in groups and eventually require massive, custom-sized aquariums.

Tiger Barb

Puntigrus tetrazona

Cyprinids
7 cm Semi-Aggressive

A highly active, schooling cyprinid famous for its striking black stripes and infamous reputation as a fin-nipper. They are boisterous and must be kept in larger groups (6+) to keep their pecking order internal. They should never be housed with slow-moving or long-finned tankmates like Bettas, Guppies, or Angelfish.

Cherry Barb

Puntius titteya

Cyprinids
5 cm Peaceful

A peaceful, schooling cyprinid endemic to the shaded streams of Sri Lanka. Unlike many of its barb cousins, the Cherry Barb is not a fin-nipper and makes an excellent community fish. They thrive in heavily planted aquariums with subdued lighting and leaf litter. Males display a striking cherry-red color, especially during spawning.

Denison Barb (Roseline Shark)

Sahyadria denisonii

Cyprinids
15 cm Mostly Peaceful

An endangered, stunningly colored cyprinid endemic to the fast-flowing streams of the Western Ghats in India. Characterized by a torpedo-shaped body with a striking red line and black stripe. They are highly active, fast swimmers that require highly oxygenated water, strong flow, and cooler tropical temperatures. They are strictly shoaling fish and can be skittish if kept in small numbers.

Duboisi Cichlid (Tropheus)

Tropheus duboisi

Cichlids - African
12 cm Aggressive

An iconic Lake Tanganyika cichlid famous for its dramatic life-stage color change. Juveniles are jet black with brilliant white polka-dots, while adults develop a blue head and a distinctive yellow or white vertical band across a dark body. They are highly aggressive toward their own kind and must be kept in large colonies (10+) to disperse aggression. They are strict herbivores that require a specialized diet to avoid fatal digestive issues.