Aquarium enthusiasts often find kohaku swordtails to be a captivating addition to their underwater ecosystems. These fish are cherished for their striking coloration, graceful appearance, and engaging behaviors. To provide the best care for your kohaku swordtail in your aquarium, it is crucial to create an environment that suits their requirements, from the setup of the tank to their feeding needs. In this guide, we will explore how to establish an ideal aquarium habitat for kohaku swordtails and address the key aspects of their care, including feeding and maintenance.

Appearance of the Kohaku swordtail

The Kohaku swordtail (Xiphophorus hellerii) is a popular aquarium fish known for its striking and vibrant coloration. The appearance of the kohaku swordtail can vary somewhat depending on the individual fish and its specific strain, but here are some general characteristics:

  • Body Shape: Kohaku swordtails have a typical swordtail body shape, which is elongated and slightly compressed from the sides. Males have a distinct elongated lower lobe on their caudal fin, which gives them their name “swordtail.”
  • Coloration: The kohaku swordtail is named after its color pattern, which is reminiscent of the traditional Kohaku Koi fish. It has a white to cream-colored body with red markings. The red markings are typically bold and cover most of the body.
  • Fins: The dorsal fin and anal fin may also have red or orange coloration, and there can be variation in the intensity and distribution of these colors.
  • Variations: There can be some variations in the kohaku swordtail’s coloration, with some individuals exhibiting more or less red, and the exact pattern of the red markings may differ.

It’s worth noting that selective breeding has led to various color strains of swordtails, so you might come across variations in color and pattern among different kohaku swordtail specimens. Additionally, proper care, water quality, and nutrition can influence the intensity of their colors.

Aquarium Setup

Setting up an aquarium to accommodate kohaku swordtails involves creating a suitable environment for their well-being and health. Here are some guidelines for setting up an aquarium for ohaku swordtails:

  • Tank Size: Kohaku swordtails are relatively small fish, but they are active swimmers, so a tank with a minimum size of 20 gallons (80 liters) is recommended for a small group of these fish. Larger tanks are even better, as they provide more swimming space.
  • Water Parameters: Maintain the water temperature between 72-78°F (22-26°C). Keep the pH level in the range of 6.5-8.0.
  • Filtration: Provide efficient filtration to maintain water quality. Kohaku swordtails are sensitive to poor water conditions, so a good filtration system is essential.
  • Substrate: Use a fine-grained substrate like sand or small gravel. Swordtails may sift through the substrate in search of food, so a substrate that won’t harm their delicate mouths is ideal.
  • Plants: Kohaku swordtails appreciate a well-planted tank. Live plants not only enhance the aesthetics but also provide hiding spots for the fish and help maintain water quality. Consider hardy, low-light plants like Java fern, Java moss, and Anubias.
  • Decor: Include driftwood, rocks, and other aquarium decorations to create hiding places and break up sightlines in the tank. This will reduce stress and aggression among the fish.
  • Lighting: Provide moderate lighting, as kohaku swordtails do not require intense lighting. A timer can help maintain a consistent light cycle.
  • Water Changes: Regular water changes (about 20-30% every 1-2 weeks) are crucial to keep water quality optimal for your swordtails.
  • Tank Mates: Kohaku swordtails are generally peaceful but can be fin-nippers, so avoid keeping them with long-finned or slow-moving fish like guppies or bettas. Suitable tank mates include other peaceful community fish that share similar water parameter requirements.
  • Breeding: If you plan to breed Kohaku swordtails, provide floating plants for fry to hide in, as adult swordtails may eat their own offspring.

Maintaining stable water conditions and providing a well-designed, well-maintained aquarium will help ensure the health and happiness of your kohaku swordtail. Regular monitoring of water parameters and observing the behavior of the fish is essential to catch and address any issues early.


Feeding kohaku swordtails a balanced and nutritious diet is essential for their health and well-being. These fish are omnivores, which means they eat a variety of foods. Here are some feeding guidelines for the kohaku swordtail:

  • High-Quality Flake or Pellet Food: A staple diet for kohaku swordtails can be high-quality flake or pellet food specifically designed for tropical fish. These foods are formulated to provide essential nutrients and can be the primary source of nutrition for your swordtails.
  • Live and Frozen Foods: Supplement their diet with live or frozen foods to provide variety and additional nutrients. Good options include brine shrimp, daphnia, bloodworms, and mosquito larvae. These foods are not only nutritionally beneficial but can also stimulate natural hunting behaviors.
  • Vegetable Matter: Swordtails also benefit from some vegetable matter in their diet. You can offer blanched spinach, zucchini, or cucumber slices. These should be soft and can be attached to a clip or skewered for easy access.
  • Feeding Schedule: Feed your kohaku swordtail 1-2 times a day, but only what they can consume in a few minutes. Overfeeding can lead to water quality issues and obesity. Monitor their eating habits and adjust the quantity accordingly.
  • Remove Unconsumed Food: Any uneaten food should be promptly removed from the tank to prevent it from fouling the water.
  • Consideration for Fry: If you have swordtail fry, they will require special food appropriate for their size, such as liquid or powdered fry food. As they grow, you can gradually introduce the same foods given to adult swordtails.
  • Variety: Providing a variety of foods in their diet ensures they receive a wide range of nutrients and helps maintain their health and vibrant colors.
  • Avoid Overfeeding: It’s important to emphasize that overfeeding is a common issue in aquariums. Excess food can lead to poor water quality and health problems for the fish. It’s better to slightly underfeed than overfeed and observe the fish for signs of hunger.
  • Water Quality: Proper filtration and regular water changes are essential to maintain good water quality, which is crucial for the health of your kohaku swordtails. Uneaten food and waste can quickly degrade water quality, so it’s important to maintain a clean tank.

By following these feeding guidelines and paying attention to the specific dietary needs and preferences of your kohaku swordtails, you can help ensure they remain healthy and vibrant in your aquarium.


Kohaku swordtails can thrive in an aquarium when provided with the right conditions. A well-maintained tank with appropriate water parameters, ample swimming space, live plants, and suitable tank mates will keep these fish healthy and happy. Additionally, offering a balanced diet that includes high-quality flakes, live and frozen foods, and occasional treats ensures their nutritional needs are met. Remember to monitor their behavior and the water quality regularly, as attentive care leads to vibrant, active, and long-lived kohaku swordtail fish in your aquatic sanctuary. With the knowledge and guidelines presented in this guide, you can create an aquatic haven that showcases the beauty of these captivating fish while ensuring their well-being.