The Gateway Killi - Blue Garneri Killifish

The Blue Gardneri Killifish is up there on our list of Highly Underrated Fish. They are gorgeous, stay small, are very interactive while being pretty easy to keep and for those of you so inclined, fairly easy to breed as well. They're perfect fish to keep in groups by themselves but also do well in community set ups. Killifish are not into killing anything unless they can eat it. Killi comes from the Dutch word for creek or stream where Killifish of all sorts are frequently found. The name literally means little stream fish. We've found them to be fairly peaceful critters, though they males will get a bit territorial with each other.

Blue Gardneri Killifish go by the scientific name Fundulopanchax gardneri, and yes, we know that sounds like something you'd get taught in a famous school for witchcraft and wizardry. These little fish were first found in the small streams, ponds, lakes and puddles of Cameroon and Nigeria. There are a number of subspecies of F. gardneri, and interestingly this is one of those fish that came from nature with several different color variants. There is much ongoing debate and research about whether these different fish (often from different streams) represent their own species or not. There are also a few aquacultured color variants that have popped up over the years, like albinos and gold variations.

In the wild, these Killifish live in an extremely varied number of habitats; from rocky streams with barely enough water to swim, to heavily vegetated ponds and lakes, and they can even flip flop across dry land when the puddle they live in starts to dry up and they go looking for another puddle! As a result of this, they also use a huge variety of spawning mechanisms. In places where there is constant water, they can reproduce year-round. In places where their homes dry up, the eggs can actually desiccate in the mud and re-hydrate later to hatch!

This huge variety of habitats also means that Blue Gardneri Killifish are generally quite adaptable when it comes to the display you choose for them and the water chemistry of that aquarium. They'll be just fine in just about any water chemistry as far as pH and hardness goes as long as you avoid extremes. They never get much bigger than two and half inches to three inches long, and don't need of ton of space. A 20-gallon aquarium would be ideal for a group of six to ten. Filtration doesn't have to be strong, if large regular water changes are consistently done. They do quite well in a surprising amount of flow, so you could have as much as 10x overturn with your filtration if you so desired. Because Gardneri Killis are so often a part of planted aquarium displays the flow of the filtration is often better balanced with the plants than the fish and the Gardneris will love very densely planted displays. One last note on the holding tank. The ability of these fish to flip-flop themselves over dry land to another puddle is amazing but also makes them high risk as far as aquarium jump outs go. Cover your tank, no excuses, no exceptions.

While you don't have to keep them in groups, they display the coolest behaviors this way and there is the added benefit of getting them to breed. If you do keep them in groups, we suggest having a couple females for every male, which should keep the males busy enough to stop them from damaging each other, or the females. Many home aquarium enthusiasts keep the Blue Gardneris as the only fish in a display, and they are absolutely interesting and cool enough to be this kind of anchor fish. They'll also be fine in community tanks and good tankmates could include fish like Neon Tetras, Danios (which will love current too), Plecos, Loaches, Corydoras, Otos, even some Dwarf Cichlids could work. This isn't an exhaustive list, but a starting place for you to develop a plan from.

It's really easy to feed Blue Gardneri Killis. They'll eat just about anything you put in front of them, as long as it fits in their mouths. Here we give them a mix of meaty foods from Gamma like Brine Plus Omega or Brine Plus Spirulina, Rotifers, Daphnia, and small Nutramar Complete Pellets. They'll also happily take a high-quality flake and any size appropriate live foods you may have on hand, or want to feed like brine, tubifex, grindal worms, etc.

They'll also eat fish eggs, including their own. So, if you want to breed them, you can choose to keep them in harems, which allow the male more breeding opportunities, but also adds more egg predators to the mix, or you can keep them as pairs, which obviously works the opposite way. Either way, the adults should be removed from the eggs as soon as possible after laying. They'll lay eggs in spawning mops or dense plants like java moss. Some hobbyists report having better success getting them to spawn in soft, acidic water, but we've also seen tons of reports of spawning success in neutral and even basic water aquariums. Pretty uniformly, people report having to increase feeding, and in some cases use live foods to get their fish into spawning condition. Babies are large enough to eat artemia nauplii and similar sized foods right away making rearing them to adulthood somewhat easier.

There is one last thing we'd like to caution you about keeping Blue Gardneri Killifish. They are a bit of a gateway fish. Among the Killifish, these are a great start point, being hardy and easy to breed, but the fish are so beautiful and engaging with their keepers, that you're likely to start down a path that ends in a room full of small tanks holding different Killifish species. You laugh now, but we've seen it happen! Regardless of whether or not you end up being a Killi-addict, these are amazing fish, that work in a variety of displays. If you're interested, head to your local fish store and ask them to get you a group of Fundulopanchax gardneri from Aquatropic today!