Killifish are pretty popular fish despite not being the most common. Some types of killifish can be found in aquarium stores, but others are a bit harder to come by.
No matter which type of killifish you choose to buy, it’s important to feed them properly. You want to make sure that the killifish stay healthy by eating a nutritious diet.
The exact requirements of each fish might differ slightly depending on the species. Many killifish are carnivorous fish, but some of them are omnivorous.
Below, you’ll learn about what killifish like to eat. This will help you to figure out the best approach so you can keep your fish happy in your fish tank.
How the Diets Vary
Most types of killifish are carnivorous. However, there are some that are omnivorous.
You need to make sure that you’re giving the fish the right nutrients. So you must feed it appropriately based on whether it’s omnivorous or carnivorous.
There will be some similarities no matter what type of fish you choose. All killifish like eating meaty types of food, but the omnivorous fish will need plant matter as well.
The first thing to do is to look up information about the type of fish that you own. Some popular killifish options, such as the blue lyretail, are omnivores.
Most of these fish are carnivores, though. The most popular killifish is likely the golden wonder killifish, and it’s a carnivore that needs to be fed a meaty diet.
What Do Killifish Eat in the Wild
In the wild, most killifish are going to do whatever they can to survive. Since most killifish are carnivorous, they’re going to seek out meaty foods.
It’s common for wild killifish to feed on insect larvae and worms. They’ll also eat small crustaceans when the opportunity presents itself.
A killifish will eat other fish if they’re small enough. These fish will eat their own young as well if they encounter them.
The omnivorous killifish will also eat algae and other types of plant matter in the wild. They still seek out meaty foods, but they supplement their diet with plant-based foods.
Will Killifish Eat Shrimp?
Killifish absolutely love to eat shrimp. It’s likely that shrimp will become a big part of the diet of these fish while under your care.
It’s common for killifish to enjoy eating many types of shrimp. You can feed these fish brine shrimp, or you can give them Mysis shrimp.
Interestingly, there are some types of shrimp that can live in fish tanks with killifish without getting eaten. Adult dwarf shrimp have been known to survive in fish tanks with small killifish, such as lampeye killifish.
Not all killifish will get along with shrimp in a community tank, though. You always have to be careful when choosing tank mates for these fish due to their carnivorous nature.
Will Killifish Eat Snails?
It’s possible that killifish could eat snails. They eat small crustaceans in the wild.
This all depends on the size of the fish in question. The size of the snail will also play a role.
Many people say that they have fed baby snails to their killifish. Adult snails might be a bit harder for many types of killifish to eat.
Some snails can live in community tanks with certain types of killifish. So you’ll simply have to research based on the individual species of killifish that you’re dealing with.
Will Killifish Eat Planaria?
Some types of fish will eat planaria worms. However, planaria worms are a bit dangerous.
These worms will often consume fish eggs, and they can also be dangerous to keep around unhealthy fish. Since killifish are carnivores, you might think that they’d be a good solution.
Most people who own killifish say that they’ve never seen them eat planaria. Since there isn’t a lot of information out there about this topic, it’d be best to avoid planaria worms.
Will Killifish Eat My Plants?
Some types of killifish will eat plants. They’ll nibble on plants if you keep them in a planted aquarium.
American flagfish are omnivorous, and they’re known to eat plants. Blue lyretails are also omnivores and might eat plants in the aquarium.
Carnivorous killifish won’t touch plants as a food source. They only want to eat meaty types of food.
The Best Diet for Killifish
Since killifish are mostly carnivores, you’re going to focus on giving them many different types of meaty live foods. Anyone who doesn’t like the idea of feeding their fish live food should shy away from the idea of owning a killifish.
Your goal is to give the fish a balanced diet that will give them the nutrients that they need. It isn’t too hard to feed these fish, but you do need to know what to give them.
Earlier, you learned that these fish like shrimp. You can easily feed them brine shrimp, and the killifish should enjoy eating frozen brine shrimp as well.
These fish eat worms in the wild. You can feed them many different types of live worms to keep them healthy in a fish tank setting.
Tubifex worms are among the most common choices. They’re easily found at pet stores and offer good nutritional value.
Both black worms and white worms can work out as well. Bloodworms will be a good choice since you can readily buy them at pet stores.
Mosquito larvae are a favorite food for killifish. This is a food that is only available seasonally, though.
They also love to eat fruit flies, beef hearts, and daphnia. The omnivorous killifish will also want to eat algae rounds and other plant-based pellets.
What to Feed Killifish Fry
Feeding killifish fry is a bit different because they will be smaller. These baby fish have tiny mouths and need to be fed types of food that they can eat.
It’s common to feed killifish fry freshly-hatched brine shrimp. These shrimp will be tiny enough for the killifish to eat.
You can also buy microworms to give to the killifish fry. These are great sources of nutrition for baby fish.
Some people choose to give killifish fry infusoria, grindal worms, and vinegar eels as well. Just make sure that your fish can fit the food in its mouth, and all will be well.
Omnivores might need to eat crushed-up algae rounds and other types of pellets. Be sure to feed your killifish fry well so they can grow strong.
How Often Should You Feed Killifish?
It’s best to feed killifish twice per day. Some choose to feed the fish once per day, but it’s more dangerous to do this.
Feeding your fish too much at once runs the risk of causing constipation issues. This can lead to swim bladder malfunctions that will make it hard for the fish to get around.
Feeding the fish twice per day will be much better. It’s safer for the fish, and you can break things up into smaller chunks.
Each time you feed the fish, you’re supposed to give them as much as they can eat in two minutes. This is the best course of action for killifish.
Ideally, you want to feed killifish in the morning before work and then feed them again when you get home from work. This is an easy schedule to remember if you work a standard 9–5 schedule.
How Often Should You Feed Killifish Fry?
Killifish fry need to be fed a little more often than adults. They’re growing, and they need the nutrients to be able to continue to get larger.
It’s best to feed killifish fry three or four times per day. Give them the freshly-hatched brine shrimp and other types of food that are good for them.
Try to maintain a consistent feeding schedule. This will allow you to keep the baby killifish in good health.
How Long Can Killifish Go Without Food?
What if you happen to miss feeding the killifish? Is it going to die right away?
Killifish will not die if you forget to feed them for a few days. These are hardy fish that can survive even if they’re made to miss a meal or two.
Some say that killifish can survive for around a week without food. There isn’t a lot of information about the upper limits of how long killifish can go without eating.
Killifish fry won’t survive as long without food as adult killifish. Also, a healthy killifish is more likely to be able to go longer without food than an unhealthy one.
Final Thoughts
You’ve learned that most killifish are carnivores. Some are omnivores and will also need to eat algae and plant-based foods.
For killifish to remain healthy in a fish tank, it’s necessary to feed them live foods. You’ll give them shrimp, worms, and other types of live foods, such as fruit flies.
Do your best to feed adult killifish twice per day to keep them healthy. Killifish fry need to be fed three or four times per day.
Since these fish are hardy, they can go without food for a little while. They will become stressed if you continue to avoid feeding them, though, and that can cause the fish to get sick.
Jeff has always enjoyed having pets, but as a child, he was drawn to his family’s fish tank. Being able to maintain a small ecosystem and observe the behaviors and interactions in the underwater world peaked his interest early on and has kept him hooked until this day. On Avid Aquarist, Jeff shares everything he’s learned about helping aquatic life survive and thrive in a home aquarium.