Welcome to the World of Killifish. For some reasons killifish are not as popular as other species although there are quite a lot of very colorful species and a variety of breeding habits. They are quite smallish and thus very well suited for nano fish tanks.

When you visit this site you most likely are experienced in killi keeping and are about to start breeding your species. Then this site is for you. I am not an expert, but experienced in breeding different killies and rainbows for several years.

This site provides you with information that are based on my experience in this hobby. I will publish my breeding succes as a diary for different species. At the moment I have 50 tanks with different species – growing – and I will publish every step I did to successfully (or not) breeding these different killifish species.

I will also offer eggs in my shop when available.

So enjoy reading and I hope you will get out something for your personal breeding success.

A short overview of the topic when you start out:

Killifish Breeding: A Comprehensive Guide

Killifish, a diverse group of freshwater fish known for their striking colors, unique reproductive strategies, and adaptability, have become increasingly popular in the aquarium hobby. Breeding killifish can be a rewarding experience for aquarists, offering the chance to observe their captivating behaviors and raise vibrant fry.

I. Introduction to Killifish breeding

Killifish belong to the family Cyprinodontidae and are distributed across various continents, including Africa, South America, North America, and Asia. Their diverse habitats range from temporary puddles to flowing streams, and they have adapted to a wide range of environmental conditions.

II. Selecting the Right Species

One of the first steps in breeding killifish is choosing the right species. There are over 1,000 recognized species of killifish, each with its unique requirements and characteristics. Here are some popular choices:

1. Nothobranchius spp.: These African killifish are known for their vibrant colors and annual life cycle, making them a favorite among killifish enthusiasts.
2. Aphyosemion spp.: This genus includes a wide variety of species with stunning colors and interesting behaviors. They are often chosen for their ornamental value.
3. Fundulopanchax spp.: Fundulopanchax species are another group of African killifish known for their beauty and ease of care.
4. Aplocheilus spp.: Asian killifish species like Aplocheilus lineatus, commonly known as the striped panchax, are popular due to their hardiness and striking patterns.

III. Aquarium Setup

Setting up an appropriate aquarium is crucial for successful killifish breeding. Here’s how to create an ideal environment:

1. Tank Size: The tank size depends on the species and the number of fish you intend to breed. A 10 to 20-gallon aquarium is suitable for a pair or a small group of killifish.
2. Water Parameters: Most killifish prefer slightly acidic to neutral water conditions with a pH range of 6.0 to 7.0 and water hardness of 5-15 dGH (degree of General Hardness). Ensure the water temperature falls within the range preferred by your chosen species, typically between 72°F to 78°F (22°C to 26°C).
3. Filtration: Use a gentle, sponge filter or a small canister filter with a gentle flow rate to maintain water quality. Killifish do not appreciate strong currents.
4. Substrate: A fine sand or gravel substrate mimics the natural habitat of many killifish species. Some species may prefer a bare bottom.
5. Aquatic Plants: Live or artificial aquatic plants provide hiding spots for the fish and create a more natural environment. Floating plants can help diffuse light and provide shaded areas.
6. Decoration: Add driftwood, rocks, and caves to create hiding places and territorial boundaries.

IV. Pairing and Conditioning

To breed killifish successfully, you need to pair compatible males and females and ensure they are in prime breeding condition:

1. Pair Selection: If you have multiple killifish, observe their interactions to identify compatible pairs. Males can be territorial, so it’s essential to provide enough hiding spots.
2. Conditioning: Before breeding, condition your fish with a varied diet. Live and frozen foods, such as brine shrimp, daphnia, and bloodworms, are excellent choices. A balanced diet ensures that the fish have the energy and nutrients required for reproduction.

V. Spawning Techniques

Killifish exhibit various reproductive strategies, including annual, non-annual, and continuous breeding. The spawning techniques can vary depending on the species and their natural behaviors:

1. Annual Killifish: Species like Nothobranchius are annual killifish, meaning they have a short lifespan and reproduce during the rainy season. Breeding these fish involves the following steps:
   • Place a pair or a group of males and females in a well-conditioned breeding tank.
   • Provide a suitable substrate for egg-laying. Some annual killifish prefer peat moss or spawning mops.
   • Maintain water conditions that simulate the onset of the rainy season: slightly warmer water and increased humidity.
   • After spawning, collect the eggs and store them in a damp, dark container with peat moss for incubation. These eggs can withstand desiccation and require a dry period to develop.
2. Non-Annual Killifish: Non-annual killifish, such as Aphyosemion species, reproduce throughout the year. The breeding process for these fish involves:
   • Providing suitable hiding places and substrate for egg-laying.
   • Monitoring the behavior of males and females. Males may display their vibrant colors and engage in courtship rituals.
   • After spawning, remove the eggs from the main tank to prevent predation by the adults.
3. Continuous Spawners: Some killifish species, like Aplocheilus lineatus, are continuous spawners. They lay eggs regularly without a specific breeding season. Breeding these fish involves:
   • Keeping a mixed-sex group in a well-maintained tank.
   • Providing hiding spots and suitable substrate for egg-laying.
   • Collecting and transferring the eggs to a separate container for incubation.

VI. Incubating and Hatching Eggs

Properly incubating and hatching killifish eggs is crucial to the success of your breeding project:

1. Annual Killifish Eggs:
   • Store the collected eggs in a container filled with peat moss or a similar substrate.
   • Keep the container in a cool, dark place for the dry incubation period, which varies by species but typically lasts several weeks to a few months.
   • After the dry incubation, rehydrate the eggs by gently adding water. Gradually increase the water level over several days to prevent shock to the developing embryos.
   • Fry will hatch once they are fully developed and rehydrated. Transfer them to a rearing tank with suitable conditions.
2. Non-Annual and Continuous Spawners:
   • Transfer eggs to a separate container with the same water conditions as the main tank.
   • Provide gentle aeration to ensure oxygenation of the eggs.
   • Monitor the eggs for signs of fungus or other issues and remove any affected ones.

VII. Rearing Fry

Successfully raising killifish fry requires attention to their dietary needs and tank conditions:

1. First Foods: Newly hatched killifish fry are tiny and require appropriate first foods, such as infusoria, paramecia, or commercially available liquid fry foods.
2. Gradual Transition: As the fry grow, you can introduce finely crushed flake foods, micro worms, baby brine shrimp, and other small live or frozen foods.
3. Water Quality: Maintain pristine water conditions in the fry tank. Frequent, small water changes can help keep ammonia and nitrite levels low.
4. Tank Size: As the fry grow, you may need to transfer them to a larger tank to prevent overcrowding.

VIII. Conservation and Responsible Breeding

In recent years, there has been a growing awareness of the need for responsible breeding and conservation efforts for killifish and other aquatic species. Many killifish species face threats in the wild, such as habitat destruction and pollution. Here are ways to contribute to conservation:

1. Avoid Wild-Caught Specimens: Whenever possible, acquire killifish from reputable breeders rather than purchasing wild-caught specimens. Captive breeding helps reduce pressure on wild populations.
2. Participate in Conservation Programs: Support organizations and initiatives that focus on the conservation of threatened and endangered killifish species. Some aquarium hobbyist groups collaborate with conservation efforts.
3. Share Knowledge: Share your knowledge of killifish breeding and conservation with other enthusiasts and the broader community to raise awareness.
4. Responsible Breeding: If you decide to breed killifish, do so responsibly. Avoid overbreeding, provide proper care, and consider the long-term welfare of the species.

IX. Conclusion

Breeding killifish is a captivating and rewarding endeavor that allows aquarists to appreciate the diversity and beauty of these remarkable fish. Whether you choose annual, non-annual, or continuous spawners, each species presents a unique breeding challenge and an opportunity to contribute to their conservation.

Through responsible breeding practices, proper care, and support for conservation efforts, aquarists can play a crucial role in preserving the natural heritage of these incredible fish. Killifish breeding is not only a hobby but also a way to promote awareness and appreciation for the aquatic ecosystems these fish call home.