Red Tailed Black Shark
Epalzeorhynchos bicolor
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.
Red Tailed Black Shark At a Glance
Red Tailed Black Shark Tank Requirements
Will Red Tailed Black Shark fit in your tank?
Care guides tell you what Red Tailed Black Shark needs, the next question is whether your tank can safely provide it. Test Red Tailed Black Shark against your tank size, maintenance needs, and the fish you already keep before you buy.
Red Tailed Black Shark Water Parameters
Red Tailed Black Shark Temperament & Compatibility
Red Tailed Black Shark 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 6.5–7.5 and a general hardness of 5–15 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.
Who Red Tailed Black Shark Is Actually For
Red Tailed Black Shark is best for a fishkeeper who expects a species with attitude and plans the tank around that behavior and can provide someone who understands its individual space requirements. It makes the most sense for a hobbyist who will actually build around its needs, especially driftwood.
The most common mistake is buying Red Tailed Black Shark for looks first and only later discovering how its adult size, behavior, or bioload changes the whole tank plan. Another frequent problem is forcing it into an over-busy community when it would do better with more room or more deliberate tankmate choices.
Red Tailed Black Shark Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Red Tailed Black Shark.
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
125 Gallon Standard
150 Gallon High
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.
Useful setup supplies
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Guidarium Editorial Desk
Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.
- Last reviewed
- April 28, 2026
- Last updated
- April 28, 2026
- Issues or corrections?
- Contact the editorial team
Plants That Suit Red Tailed Black Shark
These plants pair well with Red Tailed Black Shark based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Afzel's Anubias
Anubias afzelii
Amazon Sword
Echinodorus amazonicus
Anacharis
Egeria densa
Anubias Barteri
Anubias barteri
Baby Tears
Lindernia rotundifolia
Balansae
Cryptocoryne crispatula
Fish Similar to Red Tailed Black Shark
Rainbow Shark
Epalzeorhynchos frenatum
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
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
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.
Harlequin Shark
Labeo variegatus
The Harlequin Shark (scientifically valid as Labeo cyclorhynchus, though commonly sold as L. variegatus) is a highly territorial, bottom-dwelling cyprinid native to the Congo River basin. Famous for the spectacular cream and black mottling of juveniles, their colors sadly fade to a darker tone as they mature. They are voracious algae and aufwuchs grazers that require high water flow, smooth substrate to protect their delicate barbels, and must absolutely be kept as a solitary specimen due to their extreme intolerance of conspecifics and other bottom-dwellers.
Silver Flying Fox
Crossocheilus reticulatus
A highly active, fast-swimming cyprinid from Southeast Asia renowned for its voracious appetite for nuisance algae, including Black Beard Algae (BBA). They are distinguished from the Siamese Algae Eater by a net-like (reticulated) scale pattern and a distinct black spot at the base of the tail. They require highly oxygenated, fast-flowing water. Due to their strict social hierarchy, it is highly recommended to keep them entirely solitary or in a group of 5 or more; keeping 2 to 4 often results in the subdominant fish being bullied to death.
Blackline Rasbora
Rasbora borapetensis
The Blackline Rasbora, often sold as the Red-tailed Rasbora, is a hardy and highly active schooling fish native to Southeast Asia. Recognizable by a bold black lateral line topped with gold and a bright red caudal fin, they are peaceful but energetic. They require plenty of horizontal swimming space in the middle to upper levels of the aquarium and must be kept in schools to feel secure.