If you’re the proud owner of golden wonder killifish or are thinking about adding them to your tank, one of the most important questions you’ll need to consider is: What are the best golden wonder killifish tank mates? After all, keeping peace among your aquarium residents can make all the difference in creating a happy, healthy environment.
In this guide, we’ll explore everything you need to know about choosing the right tank mates for golden wonder killifish. Whether you’re setting up your first aquarium or upgrading your existing one, you’ll find actionable tips, a list of compatible species, and expert advice on how to keep your tank running smoothly.
What You Need to Know About Golden Wonder Killifish
Before we jump into the world of tank mates, let’s quickly go over some key facts about golden wonder killifish so you can better understand their needs and behaviors.
Golden wonder killifish (Aplocheilus lineatus) are beautiful fish with golden-yellow scales and long, sleek bodies. Native to South Asia, they’re known for their active personalities, territorial instincts, and semi-aggressive tendencies. While they are stunning to look at, they can be a bit finicky when it comes to choosing tank mates.

Live Fish – 6 Golden Wonder Killifish (Aplocheilus Lineatus)
Key Traits of Golden Wonder Killifish
- Temperament: Semi-aggressive, especially among males. They tend to be territorial, particularly when they’re feeling crowded.
- Size: They can grow up to 3-4 inches (7.5-10 cm), which is important when considering tank mates.
- Habitat: They’re usually found in slow-moving waters like ponds and marshes, so they prefer well-planted tanks with plenty of hiding spots.
- Diet: Omnivores, meaning they’ll eat a mix of plant and animal-based foods. This is something to consider when choosing tank mates, as some species may prefer different diets.
Now that we have a basic understanding of golden wonder killifish, let’s talk about the most important question: Which fish make the best golden wonder killifish tank mates?
Golden Wonder Killifish Tank Mates: The Best Matches
Golden wonder killifish are active, but they can also be territorial, especially when it comes to other males or smaller fish. However, with the right tank setup and species selection, you can create a peaceful and diverse community.
1. Tetras – Small, Active, and Peaceful
Tetras are a fantastic choice for golden wonder killifish tank mates. They are small, fast, and peaceful, which makes them less likely to provoke aggression. Some great tetra species to consider include:
- Neon Tetras: These small, colorful fish add a nice contrast to the golden wonder killifish and won’t compete for territory.
- Rummy Nose Tetras: Known for their striking red noses, these tetras are peaceful and can coexist with the active nature of killifish.
- Buenos Aires Tetras: A slightly larger species, Buenos Aires tetras can hold their own and won’t be bullied by the killifish.
Tip: Make sure your tetras are quick enough to avoid being harassed. Slow-moving or fragile species might become targets for the killifish.
2. Barbs – Hardy and Active Companions
Barbs are another great option for tank mates because they are active, hardy, and generally not bothered by the golden wonder killifish’s semi-aggressive tendencies. Some good barbs to consider include:
- Cherry Barbs: These are small and peaceful, but active enough to avoid being bullied.
- Odessa Barbs: Known for their bold colors and fast movements, Odessa barbs can keep up with the golden wonder killifish without backing down.
- Tiger Barbs: A little more assertive, tiger barbs can handle themselves well in an active tank.
Tip: While barbs are generally tough, it’s important to avoid overly aggressive species like the Green Tiger Barb. They can be too combative for golden wonder killifish.
3. Cichlids – Peaceful Species Make Great Tank Mates
Some species of cichlids can coexist peacefully with golden wonder killifish. However, you’ll need to pick species that are not overly territorial or aggressive, as this could lead to conflict. Consider these options:
- German Blue Ram: A peaceful dwarf cichlid that thrives in similar water conditions as golden wonder killifish.
- Bolivian Ram: Another peaceful cichlid that is great for community tanks and won’t challenge the dominance of the killifish.
Tip: Be cautious with larger or more aggressive cichlids. You want to make sure your tank mates won’t end up in a constant battle for space or food.
4. Rainbowfish – Bright and Beautiful
Rainbowfish are known for their vibrant colors and calm demeanor. These species are peaceful and active, which makes them ideal companions for golden wonder killifish. Some good rainbowfish species include:
- Boeseman’s Rainbowfish: Known for their bright colors, they won’t compete with killifish for territory and can add a splash of color to your tank.
- Neon Rainbowfish: Small, colorful, and peaceful, neon rainbowfish are excellent companions for your golden wonder killifish.
Tip: Rainbowfish can sometimes be a bit shy, so make sure they have plenty of plants and hiding spots to feel comfortable.
5. Livebearers – Peaceful and Adaptable
Livebearers, like guppies and swordtails, are another good option for tank mates. They are peaceful, active, and can handle a variety of water conditions. However, you should be careful with small, fragile species like guppies, as they might be seen as prey by the more territorial killifish.
- Platies: Small, colorful, and peaceful, platies are a great match for golden wonder killifish.
- Swordtails: Larger than guppies, swordtails are more likely to hold their ground and avoid aggression from the killifish.
Tip: Avoid overly small livebearers, like dwarf guppies, as they may not survive the killifish’s territorial behavior.
Species to Avoid as Golden Wonder Killifish Tank Mates
While there are plenty of compatible species, there are also some fish that are best avoided. Here are a few types of fish you should keep away from your golden wonder killifish:
1. Betta Fish – Too Aggressive for a Peaceful Tank
Betta fish, especially males, can be extremely territorial and aggressive. They’re not a good match for golden wonder killifish, as they might constantly fight over territory and resources.
2. Slow-Moving Fish – Too Vulnerable
Slow-moving fish, like goldfish or some species of loaches, are easy targets for a territorial golden wonder killifish. These fish won’t be able to defend themselves against aggression and might get injured or stressed.
3. Small Fish – Potential Prey
Small, slow, or delicate fish such as neon tetras, pygmy cories, and small shrimp can become targets for golden wonder killifish. Their natural hunting instincts may kick in, and the killifish might try to eat them.
Setting Up the Perfect Tank for Golden Wonder Killifish
Choosing the right tank mates is only one part of creating the perfect home for your golden wonder killifish. Here are a few tips to help you set up the ideal environment for these stunning fish:
1. Provide Plenty of Space
Golden wonder killifish are active swimmers, so they need plenty of space to move around. A 20-gallon tank is a good starting point for a small group of fish, while a 30-gallon tank or larger is ideal for a community setup with multiple species.
2. Create Plenty of Hiding Spots
Golden wonder killifish can be territorial, so it’s essential to have plenty of plants, rocks, and decorations to break up the space and give fish places to hide when needed. Plants like Java Fern or Amazon Sword are great choices.
3. Maintain Stable Water Conditions
Golden wonder killifish prefer slightly acidic to neutral water with a temperature range of 75-80°F (24-27°C). Regular water changes and a reliable filtration system are key to keeping the water quality high.
In Conclusion: Finding the Perfect Golden Wonder Killifish Tank Mates
Finding the right golden wonder killifish tank mates is about balancing the activity, temperament, and space needs of each species. As semi-aggressive fish, golden wonder killifish do best with other active, peaceful species that won’t invade their territory. Tetras, barbs, cichlids, rainbowfish, and certain livebearers make great companions.
By following the tips in this guide and understanding the behavior of your golden wonder killifish, you can create a harmonious and colorful aquarium that both you and your fish will love. Happy fishkeeping!