Clown Killifish – Detailed Guide: Care, Diet, and Breeding

Clown Killifish (also known as Epiplatys annulatus) is one of the most beautiful miniature freshwater fish species in the aquarium hobby. Therefore, if you are thinking about small fish for nano tanks, they should be an option for you to consider.

Clown Killifish grow quite small and prefer warm water. They are relatively easy to care for even for beginners.

There is a lot of conflicting information about Clown Killifish and since I like these little guys, I have done my best to gather all information and used my experience with them to make a proper guide with all the relevant information readily available about this species.

Quick Notes about Clown Killifish

Name	Clown Killifish
Other Names	Clown killifish, Clown killie, Banded panchax, Rocket panchax, Bony fishes, and African killifishes
Scientific Name	Epiplatys annulatus
Tank size (optimal)	10 gallons (~40 liters)
Keeping	Easy – Medium
Breeding	Easy – Medium
Size	up to 1.5 inches (~ 3.5 cm)
Optimal Temperature	73 – 76°F (23 – 25°C)
Optimal PH	6.0 – 7.0
Optimal GH	4 – 8
Optimal KH	1 – 6
Dwellers	Top
Nitrate	Less than 40
Diet	Carnivore
Temperament	Peaceful
Life span	up to 3 years
Color Form	Black bands with blue, red, and yellow fins

Taxonomy and Etymology of Clown Killifish

• Killifish

Lots of people believe that the killifish name originates from the verb to “kill”. Well, they are wrong.

The word “Killifish” have come from the Dutch word ‘Kils’ meaning ‘small stream or creek’. The term is derived from the Middle Dutch ‘Kille’.  

Therefore, Killifish should be translated as ‘Fish of the creek’.

Initially, this species was described by George Albert Boulenger in 1915. He called it Haplochilus annulatus.  After that Killifish has been known under many different scientific names such as:

• Pseudepiplatys annulatus,
• Aplocheilus annulatus, 
• Haplochilus annulatus, 
• Panchax annulatus,
• Epiplatys annulatus (current taxonomy name). 

• Epiplatys annulatus

The name Epiplatys is of Greek origin, ἐπί (epí) meaning ‘above, on top of’, and πλατύς (platýs), meaning ‘flat, broad’. The name Annulatus came from the Latin ‘annulus’, meaning ‘ring’ (banded color pattern) not annual.

Basically, Epiplatys annulatus is translated as the top-level dweller fish with a flat body and banded color patterns.

• Rocket panchax

Clown Killifish are also commonly called ‘the Rockets’ because their tales look like the flame from a rocket, especially in males.

• Clown Killifish

There is a theory that they got this name because of their glowing lamp eyes. After all, catchy names always attract buyers’ attention and also help in self-promotion. 

Natural Habitat of Clown Killifish

Clown Killifish have very restricted distributions. They are recorded in three of West Africa’s ichthyological provinces – Guinea, Liberia, and Sierra Leone where hot and wet seasons are very pronounced.

It must also be emphasized that Epiplatys annulatus is always confined in smaller pools and sedentary wetlands, never in large lakes and/or rivers with strong currents.

Description of Clown Killifish

Clown Killifish is a very small fish but they do grow up at a good pace.

Males tend to range from 1 – 1.5 inches (2.5 – 3.5 cm) long whereas their female counterparts are even smaller, reaching just 0.75 – 1.25 inches (2 – 3 cm) in length.

They look a bit like bumblebee gobies. Clown Killifish have small heads with googly, bright neon blue eyes and elongated slender bodies. Their body is adorned by 4 vertical dark stripes on their sides alternating with cream or yellowish bars between the snout and caudal-fin.

They are very colorful and grow into an absolute beauty but there are a few things to know:

• Clown Killifish can exhibit slight differences in color pattern depending on the population.
• Stressed fish can temporarily lose their color. This is especially important during shipment when they look pale and very unappealing compared to pictures.  
• Young Clown Killifish are less colorful. So, age is another aspect of body coloration. That is why do not judge too early.

They are one of the most beautiful Killifish, in my opinion, especially males. The color contrast that they have is very appealing to me.

Lifespan of Clown Killifish

Clown Killifish are short-lived fishes but they are not one of the annual types of killies. The word ‘annulatus’ should not confuse you (see above etymology).

Under optimal conditions, Clown Killifish can live anywhere from 2 – 3 years in the aquarium.

Keep in mind that growth and maturation are also closely linked to temperature. High temperatures increase their metabolism and shorten their lifespan. Therefore, Clown Killifish die sooner when kept in very warm water.

Behavior of Clown Killifish

Clown Killifish are cute, peaceful, non-aggressive, and very shy little fish. They are best kept in a species only tank or in a community tank with small and non-aggressive fish species. Be mindful, they are quite small fish so anything that can fit them in their mouths may eat them.

–       Sociality

They are social and like to be in groups. However, Clown Killifish do not shoal in the literal sense.

While they are not schooling fish, Clown Killifish display more comfortable behaviors if kept in a group.

Very important: Small groups and overcrowding can equally change behavior and cause aggression between them.

You need at least 4 – 6 of them to start.

–       Temper

Some aquarists say that Clown Killifish are very peaceful and always too busy with breeding interests to interact with the other species in the tank. Sometimes males will try to push each other but they will not harm each other.

It is true but only to some degree.

I have never seen or heard that Clown Killifish harassed other fish species. However, these fish can be pretty aggressive with each other, and conflicts between males are not always inoffensive.

I saw them injuring each other with their back fins being torn and ripped. The dominant one can bully the others until they stop eating and die off.

Luckily it does not happen very often and in most cases they solve their disputes by swimming side by side and pushing each other, to find out who will be the alpha.

Clown Killifish need to be in larger groups in order to really thrive at the same time avoid overcrowding. If you find this balance you will avoid rivalry.

My experience with Clown Killifish is that they are very reclusive and timid fish, especially females when you put them together with other fish. With time it may change a bit and they can become more open but, personally, I would not expect much.

–       Placement in Tank

Clown Killifish are mostly surface dwellers and stay near the top of the water column. They may cruise the mid and lower level of the tank periodically, however, they do stay at the surface most often.

Generally, they do not move much but when they do, they are mighty quick.

–       Activity

Clown Killifish are phenomenal jumpers. You need to have a tight lid!

Even more, if you decide you keep them, you need to be extra careful even when you open the lid to feed your fish because they may start jumping.

Features:

• Social: Yes
• Activity: Average
• Placement: Surface dwellers
• Peaceful: Yes (with other fish species)
• Jumpers: Yes.

Feeding Clown Killifish

Clown Killifish are classed as micro predators or micro-carnivores. It means that they feed entirely on other small organisms such as mosquito larva and small crustaceans. They do not eat algae.

In the aquarium, you can feed them a wide variety of meals such as:

• brine shrimp (artemia salina),
• moina,
• bloodworms,
• black worms,
• daphnia,
• fruit flies,
• grindal worms,
• mosquito larvae,
• cyclops.

Good thing though is that Clown Killifish do not require only live foods. We can feed them frozen and commercial food as well:

• fluval bug bites,
• hikari first bites,
• any kind of really small crushed-up tiny flake food.

Basically, we can give them any live or frozen food Clown Killifish can fit in their mouths.

How Often to Feed Clown Killifish?

Adults can be fed once a day whereas juveniles should be fed twice per day. 

The important rule is that you should not let Clown Killifish starve. Otherwise, despite their peaceful temper, they can turn aggressive to each other because of food competition.

How to Feed Clown Killifish?

They are diurnal animals, thus these fish should be fed during the day. 

Clown Killifish are surface feeders. Their mouths are developed to catch prey above them. They rarely pick anything on the substrate.

 Make sure it is a protein-based diet. A varied diet is always best.

Clown Killifish also have very small mouths, therefore, be prepared to grind up some flakes.

Features:

• Diet Type: Canivore
• Food Preference: Meat
• Feeding Frequency: Daily

Are Clown Killifish Plant Safe?

Yes, Clown Killifish are plant safe. They are carnivorous and do not eat live plants.

Even more, plants are recommended for them especially for breeding purposes. I will talk about it below.

Keeping and Caring for Clown Killifish

Clown Killifish care is quite easy and straightforward. Of course, you still need to address their core needs! Here are some care guidelines to help you out.

It is important that you cycle your tank before bringing fish home. Once the tank is cycled you need to check the quality of the water using a test kit.

Tank size:

The minimum recommended tank size for Clown Killifish is a 5-gallon (20-liter) tank (nano tank). Ideally, a 10-gallon tank (40 liters) will suit them way better. In large tanks they will be lost and difficult to see.

The main problem of nano tanks is that it can be really hard to keep stable water parameters in small tanks even for experienced aquarists. Smaller aquaria should be used only for breeding purposes.

If there is a choice, long tanks are better than tall tanks of the same size for keeping Clown Killifish. They like shallow water.

Important: You need to get a lid for the tank, Clown Killifish are big-time jumpers. They will be out of there before you know it!

Water parameters:

Important:  If you are buying captive-bred (for several generations) Clown Killifish you need to find out the water parameters they were bred in. If you can’t find this information, you will have to take the risk and presume that the breeder kept them in water parameters that are close to the natural ones. Related article: ·         The Ideal Water Parameters for Fish and Shrimp Keeping

Temperature: Clown Killifish can live in a wide range of temperature conditions 70 – 86°F (21 – 30°C). However, the optimal temperature in the aquarium should be in the range of 73 – 76°F (23 – 25°C). 

pH: Try to aim for a pH between 6.0 – 7.0. In nature, Clown Killifish are mostly found in slightly acidic water (less than 7.0).

I have read some reports claiming that people kept and even bred them around pH 7 – 7.5 and did not have any problems with them. Well, it might be the case that these captive-bred generations used to such water parameters. However, if you decide to do the same with fish that are not prepared for that, they will die. The same can happen if you introduce fish to optimal water parameters (as we know them) but they have already accustomed to less ‘ideal’ water parameters.

This is one of the main reasons why people fail to keep Clown Killifish. It looks like hobbyists do everything right but things can still go downhill. Of course, fish could just be poor quality or shipment stress. Stress is a really big factor.

Hardness: Clown Killifish will appreciate soft water between 4 – 8 GH. If you do not have that you will have a hard time keeping them alive. The hard water is not good for them.

Salinity: Clown Killifish is a freshwater species.

There is also information online that Epiplatys annulatus was found sometime in slightly brackish water. During my research, I could not find any verification of this. However, if it is true it will be more like an exception to the rule. Probably they have adapted to mildly brackish conditions.

Nonetheless, I would not add Clown Killifish to brackish waters.

Water Flow:

In the natural ecosystem, Clown Killifish inhabits ponds and shallow streams where the current is very slow-moving. They are surface dwellers, so any surface agitation makes them very uncomfortable and causes stress.

Therefore, still / very slow water currents are important requirements for tanks housing this species.

Filtration:

You can use sponge filters for that. Sponge filters do cause some surface agitation but not nearly as much as other filters do. Another great advantage is that sponge filters are baby safe. So, if your Clown Killifish starts breeding, the babies will not get sucked into that.

With most other filters, you will need an extra pre-filter in the form of a sponge to prevent fry from being sucked in.

Note: Once you understand the requirements of this species, it will become very easy to care for them. I have seen some professional breeders keeping them even without filtration and feeding live foods only but they had to do water changes every 1 – 2 days. Nonetheless, if you are new to this hobby, do not do that!

Lighting:

The lighting should be adapted to the needs of plants in your tank. Ideally, you need to pick floating plants or plant that do not require a lot of light. Why?

Because I noticed that too much light in the Clown Killifish tank washes out their coloration. I believe that by doing so these small fish try to camouflage from predators.

Substrate:

According to the study, in nature, the smectite clay substrate plays an important role in their breeding (egg formation and development). The absence of key breeding substrate would have doomed them to rapid extinction

In aquariums, we do not have to worry about substrate that much. We can use floating plants and plants like mosses for that.

Plants and Decorations:

Clown Killifish need a lot of plants and hiding places to be happy.

It can be all types of floating plants, fake plants, driftwood, leaves, and other decorations to enrich the environment in your tank. It is very important to minimize stress to your Clown Killifish by giving them a lot of places to hide.

Floating plants and mosses play an important role in breeding purposes. They use these plants to lay their eggs and hide fry. In addition, floating plants will help to discourage fish from jumping, when you do not have a lid.

Acclimation:

Before putting Clown Killifish into your tank do not forget to carefully temperature acclimate them.

Do not rush the process! Do it very slowly to prevent any unnecessary stress.

Clown Killifish – Male and Female Differences

There are a few indicators that give away the gender of Clown Killifish.

1. Anal fins. Males have a tail that almost looks like fire coming out of the rear end. They can have red outlined in blue or blue outlined in red anal fins. Females have more transparent anal fins with just a little bit of red in the middle of the tail.
2. Ventral fins. Males can have either bright red or bright orange. Whereas females have less developed fin extensions and are less colored.
3. Size. The females are slightly smaller than the males.

Breeding Clown Killifish

Clown Killifish are not that difficult to breed as long as conditions are good. They can breed even in a community tank but it would be better to have a separate tank for breeding purposes. Remember, there are 3 main factors for successful breeding:

1. stable and good water conditions,
2. proper diet (live food mostly),
3. keeping fry alone in a separate tank.

I have never had this problem myself but some people complained that they could not breed Clown Killifish in tanks with shrimp (to be precise Amano shrimp) and snails because they ended up eating all the eggs.

Maturity:

Depending on the temperature, Clown Killifish reach sexual maturity at 2 – 3 months old. At this time they become more colorful. So, you will definitely know the males when they mature.

Mating:

The optimal ratio of females to males is 2:1 or 3:1.

Males start following females around constantly and try to pin females against any surface.

Eggs:

Clown Killifish are egg scatterers, they are not livebearers.

Females usually lay 1 – 2 eggs each day and they can do that every couple of weeks, producing up to 10 – 20 fries per pair of adults.

Their eggs are adhesive and easily attach to plants.

Clown Killifish prefer to spawn at the surface, but mosses are also a good medium for the eggs. The structure of the plan acts like a spider web and hides the eggs and fry in it.

After fertilization, the eggs are ready to hatch within 10 – 12 days at 75 – 77 °F (24 – 25 °C).

Note: Instead of plants, some aquarists use yarn mops. This way it is easier to relocate the mop to another tank and incubate eggs away from the adults.

Hatching:

If the adults’ Clown Killifish are well-fed, they generally do not predate on their young. So, the babies can be kept in the same tank as the parents.

Unfortunately, it cannot be said the same about the juvenile from previous batches. They will eat smaller fry, therefore, it is better to separate different generations.

After hatching, the fry grow rapidly and require frequent feeding (2 times a day) such as:

• rotifers,
• moina,
• infusoria,
• newly hatched brine shrimp,
• nematodes (microworms), etc.

How to initiate spawning:

• Give Clown Killifish live foods.
• Soften up their water a bit. Adding 10 – 20 % of rainwater (distilled) will replicate the breeding season for them.

Clown Killifish and Suitable Tankmates

Because of the specific requirements, the ideal situation for Clown Killifish is a species only tank. It will also significantly improve their chances to breed.

Nonetheless, it is still possible to keep them in the community tank, as long as their tankmates are chosen with care.

–       Fish

All tank mates should have a gentle temperament and enjoy the same water parameters as the Clown Killifish. Basically, everything can bully them.

Some compatible fish tank mates are Pygmy Cory, Boraras, Panda Garra, Albino Bristlenose Pleco, Neon Tetras, Brilliant Rummynose Tetras, Harlequin Rasboras, Ruby Tetras, Dwarf Ember Barbs, Guppies, Dwarf Chain loaches, Kuhli Loaches, Endlers, Medaka Ricefish, etc.

–       Dwarf shrimp

If you are planning to keep Clown Killifish with dwarf shrimp, you should understand the risks.

Clown Killifish will not harm adult shrimp but they will definitely feed on shrimplets! At the same time, shrimp may feed on Clown Killifish’s eggs.

–       Snails:

Clown Killifish are compatible with any freshwater snail. They will do a good job in scavenging for food particles, plant matter, and algae along with the lower levels of the tank.

Avoid:

• Large and/or aggressive, and/or boisterous fishes (Cichlids, Arowanas, Tiger fish, etc.).
• Top dweller fish that can compete with Clown Killifish for food.
• Keep them away from all types of crayfish and most types of freshwater crabs. 
• Even small African Dwarf Frogs can and will try to catch small Clown Killifish whenever it is possible.

In Conclusion

Clown Killifish are beautiful small and peaceful fish that breed really easily in a well-planted tank. They are one of the best fish species for small tanks.

They are also relatively easy to breed and care for once you understand their requirements.