Pearl Danio (Danio albolineatus): Species Profile & Care Guide

Pearl Danio

The Pearl Danio (Danio albolineatus) is a captivating species of freshwater fish known for its vibrant appearance and dynamic behavior, making it a popular choice among aquarium enthusiasts. Native to the clear streams and waterways of Southeast Asia, including Myanmar and Thailand, this species thrives in environments with abundant vegetation. 

Characterized by a slender body that can reach up to 2 inches in length, the Pearl Danio exhibits a striking color palette of iridescent blue to green along its body, complemented by a distinctive horizontal orange to pink stripe that runs from its gills to the tail fin. 

Not only are they known for their beauty, but Pearl Danios are also appreciated for their peaceful demeanor and the ease with which they adapt to a variety of water conditions, making them an excellent choice for community aquariums. These active swimmers are schooling fish, preferring to be in groups, which enhances their stunning visual display and contributes to a harmonious tank environment.

Common Name(s)Pearl Danio
Scientific NameDanio albolineatus
OriginSoutheast Asia, found in countries like Thailand, Myanmar, and Laos.
Temperature68°F to 78°F (20°C to 26°C)
SizeUp to 2 inches (5 cm)
Minimum Tank Size10 gallons (38 liters) for a small group
Food & DietOmnivorous; can eat flake, live, and frozen foods such as daphnia, brine shrimp, and worm species.
LifespanAround 3 to 5 years, with proper care
Water pH6.5 to 7.5
Tank MatesPeaceful; good with other Danios, Tetras, Rasboras, and other peaceful community fish.
BreedingEgg scatterer; requires fine-leaved plants or a spawning grid for egg laying. Eggs hatch in 24-36 hours.
Common DiseasesProne to the same diseases as other freshwater fish, including Ichthyophthirius (Ich) and fungal infections. Regular tank maintenance and monitoring are essential for prevention.

Pearl Danio Care

Pearl Danio is renowned for its hardiness and ease of care, making it a popular choice among both novice and experienced aquarists. These small, active fish thrive in a wide range of water conditions, preferring temperatures between 20°C and 24°C (68°F to 75°F) and a pH range of 6.0 to 8.0. They are adaptable to various water hardness levels, though they do best in slightly soft to moderately hard water. 

Pearl Danios are schooling fish that require ample swimming space, so a tank of at least 10 gallons is recommended to accommodate a small group, ensuring they can exhibit their natural schooling behavior. Their diet is not demanding; they will readily accept a variety of foods, including flake food, frozen, and live foods. 

To keep these fish healthy and their colors vibrant, provide them with a well-planted aquarium that includes hiding spots and open swimming areas. Regular water changes and maintaining good water quality are essential to prevent stress and disease. Their resilience and straightforward care requirements make Pearl Danios an excellent choice for a community aquarium.

Food & Diet

Proper nutrition is essential for maintaining Pearl Danios’ health and vibrancy. Here are general guidelines for feeding and diet management for Pearl Danios:

Diet Composition

  • Variety is Key: Pearl Danios are omnivores and thrive on a diet that includes both plant and animal matter.
  • Basic Diet: High-quality flake food or micro pellets can serve as the base of their diet.
  • Protein Sources: Supplement their diet with live or frozen foods such as bloodworms, daphnia, and brine shrimp to ensure they receive adequate protein.
  • Vegetation: Incorporate vegetables or vegetable-based foods to provide necessary fibers. Small amounts of blanched spinach or zucchini are good options.
  • Vitamins and Minerals: Ensure their food contains essential vitamins and minerals to support overall health. Specialty fish foods often include these.

Feeding Guidelines

  • Frequency: Feed them small amounts 2-3 times a day. Overfeeding can lead to poor water quality and health issues.
  • Quantity: Only feed what they can consume in a few minutes. Excess food should not be left to decompose in the tank.
  • Observation: Watch their feeding behavior. It can help you adjust the amount and type of food to ensure all fish are eating well.

Other Considerations

  • Water Quality: Good diet practices go hand in hand with maintaining water quality. Uneaten food should be removed to prevent water pollution.
  • Social Behavior: Pearl Danios are schooling fish. They are likely to eat more comfortably and actively in the presence of their school.

Balancing the diet of Pearl Danios with a mix of quality flake or pellet food, supplemented with live or frozen protein sources and vegetables, will help keep them healthy, vibrant, and active. Always pay attention to the quantity of food to avoid overfeeding and ensure the tank is clean to maintain their well-being.

Temperature & Water Parameters

To ensure the health and well-being of Pearl Danios, it’s important to maintain the right environmental conditions in your aquarium. Here are the recommended parameters:

  • Temperature: Pearl Danios thrive in temperatures ranging from 20°C to 24°C (68°F to 75°F). Maintaining the temperature within this range ensures that the fish remain active and healthy. It’s crucial to use an aquarium heater in cooler climates to keep the water temperature stable.
  • pH Level: The optimal pH level for Pearl Danios is between 6.5 and 7.5. This slightly acidic to neutral pH range is conducive to their health and well-being. Regularly testing the water’s pH and making adjustments as necessary can help maintain these conditions.
  • Water Hardness: Pearl Danios do best in soft to moderately hard water, with a general hardness (GH) between 5 and 19 dGH. This range of water hardness supports their physiological processes and helps prevent stress.
  • Water Quality: Like all aquarium fish, Pearl Danios require clean, well-oxygenated water to thrive. Regular water changes (about 20-25% of the tank volume per week) are recommended to remove toxins like ammonia, nitrites, and nitrates. Using a good filtration system will help maintain water clarity and quality.

By staying within these parameters, you can create a healthy and stimulating environment for your Pearl Danios, allowing them to exhibit their natural behaviors and vibrant colors. Regular monitoring and adjustments to the tank’s conditions are essential for the long-term health of your fish.

Tank Setup

Setting up a tank for Pearl Danios requires creating an environment that closely mimics their natural habitat to ensure their health and happiness. Here are some key factors to consider when setting up your aquarium:

Tank Size

Pearl Danios are active swimmers and thrive in groups, so a minimum of a 20-gallon tank is recommended to provide adequate space for swimming and to accommodate a small school of these fish.

Water Conditions

  • Temperature: Maintain the water temperature between 68°F and 77°F (20°C to 25°C).
  • pH Level: Aim for a pH level between 6.5 and 7.5.
  • Hardness: Water hardness should be kept in the range of 2 to 15 dGH.

Filtration and Water Movement

Pearl Danios appreciate well-oxygenated water with a moderate current. A good filtration system is essential to keep the water clean and well-oxygenated without creating excessively strong currents.

Tank Setup

  • Substrate: A dark substrate can help the colors of the Pearl Danios stand out. Sand or fine gravel works well.
  • Plants and Decor: They enjoy a tank with plenty of live plants, driftwood, and rocks to mimic their natural environment and provide hiding spaces. Plants like Java Fern, Anubias, and Water Wisteria can create an ideal environment.
  • Lighting: Standard aquarium lighting is sufficient, as it will support plant growth without stressing the fish.


Regular water changes (about 20-25% weekly) are necessary to maintain water quality. Test the water parameters regularly to ensure they remain within the ideal ranges.

By following these guidelines, you can create a healthy and visually appealing environment for your Pearl Danios. Remember, the key to a successful aquarium is regular maintenance and monitoring of water conditions to ensure the well-being of your fish.

Behavior & Temperament

Understanding the behavior and temperament of Pearl Danio is essential for those looking to keep them in home aquariums. Here are some key aspects:

Social Behavior

  • Schooling Fish: Pearl Danios are highly social and prefer to be in groups. Keeping them in schools of at least 5-6 individuals is recommended to ensure their well-being. In a school, they exhibit more natural behaviors and are less stressed.
  • Peaceful Nature: They are known for their peaceful temperament and can coexist well with other peaceful and similarly sized fish species, making them an excellent choice for community tanks.

Activity Level

  • Active Swimmers: These fish are very active and enjoy swimming in open water. They are often seen darting around the tank, especially if given plenty of space to explore.
  • Surface Dwelling: While they can be found at various levels of the tank, they often prefer the middle to upper sections of the water column.

Environment and Interaction

  • Environmental Enrichment: They thrive in environments that mimic their natural habitat, which includes plenty of plants and hiding spaces. Such setups help reduce stress and promote natural foraging behaviors.
  • Interaction with Others: Pearl Danios are generally not aggressive towards other tank mates. However, like many schooling fish, they may occasionally display minor nipping behavior, especially if they are not in a sufficiently large group or if the tank is overcrowded.

In summary, Pearl Danios are a joy to keep due to their vibrant appearance and lively behavior. Their peaceful nature and adaptability make them suitable for a wide range of community aquarium setups. 

Tank Mates

Ideal tank mates for Pearl Danios should match their peaceful nature and be able to thrive in similar water conditions. Here are some general guidelines and specific fish species that can cohabit well with Pearl Danios:

General Guidelines for Selecting Tank Mates:

  • Peaceful Nature: Choose fish that are peaceful and unlikely to bully or be bullied by the Danios.
  • Similar Size: Fish of a similar size are ideal, as smaller fish could be intimidated, and much larger fish could see Danios as prey.
  • Water Parameters: Ensure the tank mates can thrive in the same water conditions. Pearl Danios prefer temperatures between 20°C to 24°C (68°F to 75°F), with a pH range of 6.5 to 7.5.
  • Swimming Level: Since Danios are top to mid-level swimmers, it’s good to have species that occupy different areas of the tank to avoid overcrowding in one zone.

Suitable Tank Mates for Pearl Danios:

  • Tetras: Many tetra species are peaceful and share similar water parameter requirements, making them good companions.
  • Rasboras: Small rasboras, like the Harlequin Rasbora, are peaceful and can match the Danios in terms of activity and size.
  • Corydoras Catfish: These bottom dwellers are peaceful and can help keep the substrate clean without disturbing the Danios.
  • Guppies and Mollies: Both are peaceful, though care should be taken with guppies if you have very active Danios, to prevent fin nipping.
  • Loaches: Certain loaches, like the Kuhli Loach, are peaceful and occupy the bottom level of the tank, complementing the Danios’ swimming area.
  • Dwarf Gouramis: These are peaceful and can add color and variety to the tank, though they should be monitored to ensure they’re not bullied or stressed by the active Danios.


  • Avoid Aggressive or Much Larger Species: Aggressive fish or much larger predatory fish can stress or harm the Danios.
  • Monitor for Bullying or Stress: Even within generally compatible species, individual temperament can vary. Monitor the tank to ensure all fish are cohabiting peacefully.
  • Aquarium Size and Setup: Ensure the aquarium is large enough to accommodate the active swimming of Danios and their tank mates, with plenty of space for all fish to establish their territory.

When introducing any new fish to an aquarium, it’s crucial to quarantine new arrivals to prevent the spread of disease and to monitor interactions closely to ensure compatibility.

Common Disease & Health Issues

The Pearl Danio is a popular freshwater fish among aquarium enthusiasts due to its beautiful appearance and peaceful nature. However, like all aquatic pets, they are susceptible to certain health issues and diseases. Here are some common health problems and diseases that can affect Pearl Danios:

  • Ichthyophthirius multifiliis (Ich or White Spot Disease): This is a very common parasitic infection in freshwater fish. It is characterized by white, grain-like spots on the skin, fins, and gills. Fish may also exhibit signs of distress, such as rubbing against objects, rapid breathing, and lethargy.
  • Fin Rot: This bacterial disease causes the edges of the fins to fray or rot away, often starting with a white milky edge to the fins. It can progress to body rot if not treated promptly. Poor water quality and stress are common contributors to this condition.
  • Velvet Disease (Oodinium): Caused by dinoflagellate parasites, this disease presents as a fine, gold or rust-colored dusting on the skin of the fish. Infected fish may scratch against objects due to irritation, show rapid gill movement, and become lethargic.
  • Bacterial Infections: Bacterial infections can manifest in various ways, including ulcers, sores, and red streaks on the body of the fish. Poor water conditions and injuries can increase susceptibility to bacterial infections.
  • Fungal Infections: These are less common but can occur, especially in fish that are already weakened by stress, injury, or other diseases. Fungal infections usually appear as cottony growths on the fish’s body, mouth, or fins.
  • Swim Bladder Disease: This condition affects the fish’s ability to regulate its buoyancy, leading to swimming difficulties such as floating upside down, sinking to the bottom, or swimming at an angle. It can be caused by overfeeding, constipation, or infection.

To prevent these health issues, it’s important to maintain good water quality in your aquarium, ensure proper nutrition, and observe your fish regularly for any signs of disease. Quarantining new fish before adding them to your main tank can also help prevent the spread of diseases. If you notice any signs of illness in your Pearl Danios, prompt treatment is crucial to prevent the disease from spreading or worsening.


When it comes to breeding Pearl Danios, there are several key factors to consider to ensure a successful breeding process. Here’s an explanation of their breeding behavior and a guide on how to breed them:

Breeding Behavior

  • Group Dynamics: Pearl Danios are schooling fish and exhibit more natural behaviors when kept in groups. For breeding purposes, it’s often recommended to maintain a group with a higher number of females to males to prevent the females from being overly harassed by males.
  • Spawning Trigger: These fish are often stimulated to spawn by changes in water conditions, mimicking the onset of the rainy season in their natural habitat. A slight drop in temperature followed by a gradual warming, combined with fresh water changes, can trigger spawning.
  • Spawning Process: Pearl Danios are egg scatterers, meaning they do not care for their eggs after laying. During spawning, the females release eggs while the males fertilize them in open water or as they fall onto the substrate or plants.

How to Breed Pearl Danios

  • Set Up a Breeding Tank: Prepare a separate tank for breeding, around 10-20 gallons in size. The tank should have a sponge filter for gentle filtration without sucking up the eggs. Place a spawning substrate at the bottom to protect the eggs from being eaten. This can be a layer of marbles or a fine mesh that allows eggs to fall through out of reach of the adults.
  • Water Conditions: Ensure the water is soft and slightly acidic to neutral (pH 6.5-7.0) with a temperature around 78-80°F (25-27°C). Before breeding, mimic a rainy season effect with water changes and slight temperature variations to trigger spawning.
  • Condition the Breeders: Feed the breeding group high-quality live or frozen foods such as brine shrimp, daphnia, or bloodworms. This helps condition the fish for spawning, improving both the quantity and quality of eggs.
  • Initiate Breeding: After conditioning, select the healthiest and most active males and females for breeding and introduce them to the breeding tank. Spawning typically occurs in the early morning.
  • Post-Spawning Care: After spawning, remove the adults from the breeding tank to prevent them from eating the eggs. The eggs usually hatch within 24-36 hours, and the fry become free-swimming a few days later.
  • Feeding the Fry: Start feeding the fry with infusoria or commercially available liquid fry food until they are large enough to eat baby brine shrimp or microworms.

Key Points to Remember

  • Monitor water quality closely in the breeding and fry tanks, as poor conditions can lead to disease or low survival rates.
  • Patience is key. Not every attempt at breeding may be successful, but consistent care and optimal conditions can lead to successful spawning.

Breeding Pearl Danios can be a rewarding experience, allowing hobbyists to observe the fascinating lifecycle of these beautiful fish. With proper preparation and care, even beginners can successfully breed Pearl Danios.

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