Aquarium enthusiasts often seek unique and captivating species to add to their collections, and the red tail shark fits this description perfectly. Native to the freshwater basins of Thailand, this striking fish, with its vivid red tail and sleek black body, is not only a visual delight but also an interesting species to observe and care for. However, keeping a red tail shark healthy and happy in an aquarium setting requires specific knowledge and commitment. From understanding its natural behavior and dietary needs to creating an optimal tank environment, every aspect plays a crucial role in the well-being of these beautiful fish. In this comprehensive guide, we delve into the essential aspects of caring for red tail sharks in home aquariums, covering everything from tank requirements to feeding habits, ensuring that both novice and experienced aquarists can provide the best care for these unique aquatic creatures.


Appearance and physical characteristics of the red tail shark (Epalzeorhynchos bicolor) are quite unique, making it a distinctive and popular choice for freshwater aquarium enthusiasts. Here’s a detailed description:

  • Appearance: The red tail shark is known for its striking coloration. It has a deep, velvety black body that contrasts sharply with its bright red tail. This stark color difference is one of its most notable features.
  • Size: Regarding size, in adulthood, the red tail shark typically reaches about 6 inches (15 cm) in length, making it suitable for medium to large aquariums.
  • Body Shape: The fish has a streamlined body, resembling that of a shark, which inspires its common name. This sleek body design enables agile and swift movements in the water.
  • Fins: Apart from its red caudal (tail) fin, the red tail shark has a dorsal fin that stands upright and is also black in color. The other fins are relatively small and proportionate to its body, aiding in its nimbleness.
  • Eyes: The eyes of the red tail shark are relatively small and can appear to have a slight glint due to their positioning and the way they reflect light.
  • Scale Texture: The scales of the red tail shark have a smooth texture, contributing to its sleek appearance and aiding in efficient swimming.

Understanding these physical characteristics can help aquarists and enthusiasts easily identify the red tail shark and appreciate its unique beauty in a freshwater aquarium setting.

Natural Habitat of the Red Tail Shark

The red tail shark has a very specific and limited natural habitat and distribution, which is quite fascinating:

  • Original Habitat: The red tail shark is originally from Thailand. Its natural habitat is the streams and rivers of the country, particularly in the Chao Phraya and Mae Klong basins. These waters provide the perfect environment for the red tail shark, with their tropical climate and varied underwater landscapes.
  • Water Conditions: In its natural habitat, the red tail shark thrives in freshwater with a moderate current. The waters are typically well-oxygenated and have a good amount of cover in the form of rocks, vegetation, and driftwood. This environment provides them with ample hiding spots as well as open areas for swimming.
  • Geographic Distribution: Historically, red tail sharks were found throughout much of Thailand’s inland waters. However, their distribution has become more limited in recent years.
  • Current Status in the Wild: Unfortunately, the red tail shark is now considered almost extinct in the wild. As a result, virtually all red tail sharks in aquariums today are bred in captivity.

The story of the red tail shark’s habitat and distribution is a poignant reminder of the impacts of environmental change and human activities on aquatic species. Their current status highlights the importance of sustainable practices in both the aquarium trade and in the management of natural waters.

Behavior and Temperament

The behavior and temperament of the red tail shark are important aspects to consider, especially for those who keep them in home aquariums. These characteristics are quite distinctive:

  • Territorial Nature: Red tail sharks are known for their territorial behavior, especially as they mature. They often claim a certain area of the aquarium as their own and can become aggressive towards other fish that enter this space. This territoriality is more pronounced in smaller tanks where space is limited.
  • Aggression Towards Similar Species: Their aggression is particularly directed towards fish that resemble their own species or have similar body shapes and colors. This includes other bottom-dwelling fish or those with a similar coloration.
  • Swimming Patterns: Red tail sharks are active swimmers and often patrol the bottom of the tank. They are known for their agile and swift movements, darting around rocks, plants, and other tank decorations.
  • Interaction with Other Fish: While they can be aggressive towards similar species, red tail sharks can coexist peacefully with other types of fish, particularly those that occupy different areas of the tank. Fast-swimming and mid-to-top dwelling fish are usually better tank mates.
  • Solitary Nature: They are generally solitary and do not form schools. In an aquarium setting, it’s usually recommended to keep only one red tail shark to prevent aggressive encounters.
  • Hiding Behavior: Despite their active nature, red tail sharks also appreciate having hiding spots in their environment. They may retreat to these spots when they feel threatened or stressed.

Understanding these behavioral patterns is crucial for anyone considering adding a red tail shark to their aquarium. It helps in ensuring the well-being of not only the red tail shark but also the other inhabitants of the tank. Proper tank size, appropriate tank mates, and providing enough hiding places can help mitigate some of the more challenging aspects of their behavior.

Tank Mates for Red Tail Sharks

Choosing tank mates for red tail sharks requires careful consideration due to their territorial and sometimes aggressive nature. Here are key factors to consider:

  • Avoid Similar Species: Red tail sharks tend to be aggressive towards fish that resemble them in size, shape, or color. This includes other bottom-dwellers or shark-like fish. It’s advisable to avoid keeping them with other red tail sharks or similar species to prevent territorial disputes.
  • Choose Different Water Column Dwellers: Opt for fish that inhabit different levels of the aquarium. Red tail sharks are primarily bottom dwellers, so fish that swim in the middle or upper parts of the tank are less likely to encroach on their territory.
  • Size and Temperament of Tank Mates: Choose tank mates that are neither too small nor too timid, as they might get bullied. Similarly, very large or aggressive fish might harass the red tail shark. Ideal tank mates are peaceful or semi-aggressive and of a similar size.
  • Fast-Swimming Fish: Fish that are quick and agile can better avoid any potential aggression from the red tail shark.
  • Community Fish Compatibility: Generally, community fish that are peaceful and not fin nippers can coexist with red tail sharks. Some examples include barbs, danios, and some types of tetras.
  • Avoid Fin-Nippers: Steer clear of species known for fin-nipping, as they can harass the red tail shark, leading to stress and injury.
  • Large Aquarium Requirement: A larger tank (minimum of 55 gallons/220 liters) is recommended, as it provides more space for all fish to establish their own territories and reduces conflicts.
  • Monitor Interactions: Even with careful selection, individual temperaments can vary. It’s important to monitor the interactions in the aquarium and be prepared to rehome fish if aggressive behavior becomes an issue.
  • Aquatic Environment: Ensure that the tank environment suits all inhabitants, not just the red tail shark. This includes water parameters, temperature, and hiding places.

By considering these factors, you can create a harmonious aquarium environment that caters to the needs of a red tail shark while ensuring the safety and well-being of its tank mates.

Diet and Feeding

The diet and feeding habits of the red tail shark in an aquarium setting are important for their health and well-being. Here’s an overview of their dietary needs and feeding practices:

  • Omnivorous Diet: Red tail sharks are omnivores, which means they need a varied diet that includes both plant and animal matter. In the wild, their diet consists of algae, plant material, small crustaceans, and insect larvae.
  • Commercial Fish Food: In an aquarium, they can be fed high-quality commercial fish food such as flakes or pellets designed for freshwater fish. These foods usually provide a balanced diet and are convenient to use.
  • Algae and Plant-Based Foods: Since they naturally consume algae, including some plant-based foods in their diet is beneficial. Algae wafers, spirulina flakes, and blanched vegetables like zucchini, lettuce, or cucumbers can be good options.
  • Protein Sources: Supplement their diet with occasional protein-rich foods like brine shrimp, daphnia, bloodworms, or tubifex worms. These can be offered as live, frozen, or freeze-dried varieties.
  • Feeding Frequency: Feed adult red tail sharks once or twice a day, providing enough food that they can consume within a few minutes. Overfeeding should be avoided as it can lead to health issues and pollute the aquarium water.
  • Bottom Feeding Habits: Since red tail sharks are bottom dwellers, ensure that the food reaches the bottom of the tank. Sinking pellets or wafers are ideal for this purpose.
  • Special Dietary Requirements: While red tail sharks are not known to have specific special dietary needs, a balanced diet that reflects their omnivorous nature is crucial for their health. Variety in their diet helps prevent nutritional deficiencies.
  • Water Quality and Feeding: Maintain good water quality by not overfeeding and regularly cleaning the tank. Decomposing food can deteriorate water quality, which can affect the health of the fish.
  • Observation: Regularly observe their feeding behavior. Changes in appetite or feeding habits can be early indicators of health issues or stress.

By providing a balanced diet and adhering to good feeding practices, you can ensure the health and longevity of your red tail shark. Remember, a healthy diet contributes significantly to the overall well-being of fish in an aquarium.

Red Tail Shark – All You Need To Know
Red Tail Shark – All You Need To Know

Aquarium Setup

Caring for red tail sharks in an aquarium involves several key aspects to ensure their health and well-being. Here’s a detailed guide:

  • Tank Size: Red tail sharks are active swimmers and need ample space. A minimum tank size of 55 gallons/220 liters is recommended. Larger tanks are better, especially if you plan to keep other fish with them, as this helps reduce territorial aggression.
  • Tank Setup and Decorations:
    • Substrate: A soft, fine substrate is ideal as it mimics their natural riverbed environment and prevents injury.
    • Plants: Live plants are recommended as they provide hiding places and help maintain water quality. Ensure the plants are securely rooted as red tail sharks can be quite active.
    • Decorations: Include rocks, driftwood, and caves to create hiding spots and break lines of sight, reducing stress and territorial behavior.
  • Water Conditions:
    • Temperature: Maintain a water temperature between 72°F and 79°F (22°C – 26°C).
    • pH Level: The pH should be kept between 6.5 and 7.5.
    • Hardness: Moderate water hardness is ideal.
  • Filtration: A high-quality filtration system is crucial to keep the water clean and well-oxygenated. Red tail sharks thrive in well-oxygenated water with a moderate current, so ensure the filter provides adequate flow without creating excessively turbulent conditions.
  • Lighting: Standard aquarium lighting is sufficient. If you have live plants, ensure the lighting also supports their growth needs.
  • Water Changes and Maintenance: Regular water changes (about 25-30% per week) are essential to remove toxins and keep the water parameters stable. Regular maintenance also includes cleaning the substrate and checking the filter.
  • Feeding Area: Designate a specific area for feeding that allows food to sink to the bottom, as red tail sharks are bottom feeders.
  • Tank Mates: Choose tank mates carefully. Avoid other bottom dwellers or fish that look similar to the red tail shark to prevent aggression. Ideal tank mates are peaceful or semi-aggressive species that occupy different levels of the tank.
  • Avoid Overcrowding: Too many fish in a limited space can lead to increased stress and aggression in red tail sharks.
  • Monitoring: Regularly check the fish for signs of stress or illness and monitor water parameters using a test kit.

By following these guidelines, you can create a healthy and stimulating environment for your red tail shark. Remember, the key to successful aquarium care is consistency in maintenance and attention to the specific needs of the species you are keeping.


Caring for red tail sharks in an aquarium is a rewarding experience that requires attention to detail and a commitment to understanding their specific needs. By providing a spacious tank, appropriate tank mates, a balanced diet, and regular maintenance, you can ensure a healthy and stress-free environment for these captivating fish. Remember, the success of keeping red tail sharks lies in replicating their natural habitat as closely as possible and respecting their behavioral tendencies. With the right care, these striking fish can be a stunning addition to any freshwater aquarium, bringing a unique dynamic to the underwater world you create. Whether you’re a seasoned aquarist or a beginner, the red tail shark offers an intriguing opportunity to engage with the fascinating world of aquarium keeping, highlighting the beauty and diversity of aquatic life.