Home » Fish Guides » Baby whale fish (Brienomyrus brachyistius) | Ultimate Care Guide

Baby whale fish (Brienomyrus brachyistius) | Ultimate Care Guide

Baby whale fish (Brienomyrus brachyistius) is one of the most popular freshwater aquarium fish all around the world. Do not confuse them with whales; they are neither true whales or dolphins. They have this whale-like face and hence got the name. 

This is a species of elephant fish from the family Mormyridae. This species is native to West Africa. In the wild, they mainly associate with the murky waters. Baby whales are more active at night time than daytime. 

The most unique feature of them is, the baby whales have an organ that can produce electric signals. This electric organ can produce electric signals with special frequencies and patterns. They use these specific signals to communicate with each other. Moreover, electric signals help them to navigate in the water.  

Although they are not true whales, baby whale fish has a large brain and they are highly intelligent. The male baby whale can grow up around 8 inches and the female can grow up larger than the male fish. This amazing freshwater creature can live around 6 to 10 years in the wild. 

Further, you should have to provide specific requirements to grow them in your aquarium. Additional reading helps you to grab more knowledge about how to rear and care for baby whale fish.

One look Care guide

Scientific nameBrienomyrus brachyistius
Common nameBaby whale fish , mormyrid electric fish, Elephant fish, Whale African black
Care levelModerate
Native toWest Africa / fresh water riversThe Gambia to the Democratic Republic of the CongoMay also be present in the upper reaches of Senegal  including Niokolo-Koba National Park
Color Black
Tank size30 gallon (Minimum)
Preferred temperature78 -82o F
Other water parametersAmmonia : 0 Nitrate: 0 Nitrites : 0
SizeAdult male 8 inch , Adult female more than 8 inch
Temperament Semi-Aggressive
Recommended tank matesElephant Noses,
African Black
Knife fish
Synodontis Catfish
Clown Loaches
Preferred foodCarnivore:
Live food
Frozen foods
Blood worms
Freeze-dried fish foods
Feeding frequency2-3 times per day
breedingDifficult in captivity

Appearance of baby whales

They have a dull black color body. If you look at them closely, you can see their body is composed of white and black small patches.

The male fish can reach around 8 inches when they become adults. The adult female baby whales are quite bigger than male fish. The baby whale mouth is quietly different from other fish mouths. 

Apart from their unique head, they are famous because of their electric organ. Using this organ they can produce small electricity that helps them to transfer messages with each other. 

Further, these electric signals use to navigate in the water column. This electric organ comprises thousands of tiny cells called “Electrocyts”. Each electrocyts can produce a pulse. The speed of the pulse same as the speed of the nerve system signals and muscle actions.

Other names of baby whale fish?

They are generally called Elephant fish and baby whales. Other than that, they are also known as Mormyrid electric fish and Whale African black. They have a special ability to produce a low level of electricity in their body.Thus, they are called Electric fish.

How big do baby whale fish get?

Baby whale fish have medium size bodies. The adult fish size is around 8 inches and female fish are larger than male fish.

Their size is a benefit to the aquarist. Because you do not need to worry about the tank size too much. The 30-gallon tank is enough to rear baby whale fish.

Behavior of the baby whale fish

Baby whale fish have a good personality. In the wild, they behave as schooling fish and like to swim as a group. 

They are mainly found in West African river streams. In the wild, they live under root mats, dense floating vegetation, or live along the edge of the river. They mainly inhabit the benthic water column of the river.

But in captivity, they show quite different behavior. In the aquarium, they like to live alone. Thus, do not put two baby fish together. Because baby whales will fight with each other. 

Further, they like to inhabit cavities and caves. They prefer to hide in those holes. Further, they are more active at night rather than day time.

Is baby whale fish aggressive?

It depends on several factors. Environmental factors and biological factors can be a reason for their aggressiveness. Normally they are more aggressive when they become large adults. 

Hence, do not add small schooling freshwater fish with them. Moreover, they show aggressive behaviors when they are ready to breed. They transfer electric signals with each other and communicate with the opposite gender in the breeding period.

Further, If you put a few baby whales (3, 4 fish) together, they show aggressive behaviors. Because the strongest fish tend to disturb other baby whales. It causes damage to other baby whales. 

Therefore other fish live with huge stress. To overcome this issue, you can add 6 or more fish into the quite larger lank (70 gallons). Then the strongest baby fish become less aggressive. Because they love to swim as a school.

Do baby whale fish bite the same variety?

They show some aggressive behavior when you put them with a few baby whales. Strong baby whales try to bite and attack other baby whales that live in the same tank. Thus, add some more baby whales to the tank or leave one fish alone to overcome this issue.

baby whale fish lifespan

Generally, they live around 6 to 10 years in their natural environment. But in captivity, it depends on your care. You should provide preferable water quality parameters and quality food for them. Baby whales’ lifespan depends on the water temperature, pH value, tank size, and water cleanness. 

The filter system plays a major role in captivity. It removes fish waste from your tank and stabilizes water quality parameters. If fish waste accumulates in the tank, it will generate ammonia, nitrate, and nitrite compounds. High doses (10ppm) of these compounds are lethal to most of the fish species including baby whales.

Baby whale fish care in Aquariums

baby whale fish tank size

Adult baby whale size is around 8 inches. Thus their space requirement is quite smaller than other larger fish varieties. They can live peacefully in a 30-gallon tank. But If you can provide more space than 30 gallons, it is better.  

How many baby whale fish should be kept together per gallon?

Do not add 2, 3, or 4 baby whales together. Because when you add a few of them together, the strong baby whale will attack other baby whales. It causes stress for other baby whales.  

If you can add 6 baby whales or more, it is better. Because baby whales show less aggressiveness when they live in a large group. In their natural habitat, they show schooling behavior. Make sure to carefully observe your baby whale behaviors. Because the strongest fish can fight with other baby whales. 

Tank setup

The tank setup should have the following equipment. 

  • Bio filter
  • Aquarium heater
  • Aquarium thermometer
  • Hiding caves
  • Gravel
  • Tank roof

Filter system

The 30-gallon tank is enough for baby whales. But they love to spend time in pristine water. Thus, an efficient bio filter should be installed in the tank. It will remove fish fecal matter from the aquarium and prevent ammonia production. You can use a bio filter.

Aquarium Heater

An aquarium heater is an essential tool. Because maintaining water temperature is essential. Your fish tank temperature can change due to the climate changes. Hence, install a proper aquarium heater for your baby whale tank to enhance their life span. 

Because they are unable to tolerate fluctuations of the water temperature. Further, you can purchase a digital aquarium thermometer from the shop. Set it in your tank. Then you can monitor water temperature regularly.

Hiding places

Gravel and hiding caves provide a home for baby whales. They highly prefer to associate with cavities and caves. Thus, you can put some ornaments for that purpose. You can set some mud pots, mud houses, or some ornaments like that. 

Tank roof

The tank roof is an essential part. Because baby whales are active jumpers. Therefore you must set up a tank roof for your baby whale tank to protect them.

Lightning for baby whale fish tank

In the wild, they live in cloudy water at benthic columns. The light level of that water column is quite low and limited. Thus, they prefer dim light conditions in captivity too. You can add some aquatic plants and floating plants to provide some natural darkness.

Water quality condition

Water quality

Do not add tap water directly to your tank. Because it may contain lots of chlorine that is used for water purification. Chlorine is toxic to most fish including baby whales. Thus, use treated freshwater to rear baby whales. 

You can use a dechlorinator to increase the chlorine disposal procedures. If not, put water into a separate container and add tap water to it. Then keep it for 2, 3 days. Within two, three days chlorine evaporates. Then add treated water to your baby whale fish tank. 

Water temperature

You should maintain water temperature around 78-82 Fahrenheit. You can establish an aquarium heater to maintain the water temperature steadily. An Aquarium thermometer gives a digital measurement of tank water temperature. Make sure to maintain the temperature at a constant level. 

The pH level of water

Generally, most freshwater fish live around 6.5-8 pH level ranges. Thus, baby whales also can live at neutral pH levels. portable pH meters are available in the market. You can measure the pH level of water to ensure that water is suitable for your baby whale or not. 

Ammonia, Nitrate, and Nitrites levels

Normally these compounds are produced by fish fecal matters and uneaten food particles. Thus, make sure to add the correct amount of food to your fish. uneaten food should be removed immediately from the water. When these food materials deteriorate, it produces lots of ammonia.

If ammonia, nitrate, and nitrites levels exceed 10 ppm, it is severe. It will kill your baby whale fish.

How to feed baby whale fish?

Food types

They are carnivorous fish species. Carnivores need foods that contain a high level of protein. You can provide live, frozen, formulated, or freeze-dried meaty food for their diet. Below I mentioned popular foods for baby whales. You can easily purchase those foods from the market.

  • Black worms
  • Blood worms
  • Frozen blood worms
  • Live Brine Shrimp
  • Frozen Brine shrimp
  • Ghost shrimp 

In the natural habitat, baby whales feed on benthic and allochthonous invertebrates. They eat insect larvae, insect debris, and other small creatures.

Feeding frequency

You should add food two or three times per day for baby whales. Do not add large quantities. Add small quantities and observe their feeding behaviors. If they finish the food before two minutes add a few amounts of feed again. If not, stop feeding. You must provide food that they can eat within 2 minutes. 

You must remove excess food particles from the tank immediately after they eat. Because fish food contains a high level of protein. If excess food deteriorates in the tank, it will produce ammonia which is highly toxic to most fish.

baby whale fish breeding 

male vs. female fish differences and Identify 

They show sexual dimorphism. Adult female baby whales are larger than male baby whales. The most important thing is you can recognize male and female baby whales by their electric signal frequency.

You do need the expert knowledge and need specific tools to identify it. Mature male baby whales produce a 2.3ms long pulse and adult female baby whales produce a 0.9 ms long pulse.  

How to breed baby whale

Breeding baby whales in captivity is quite difficult. But several researchers did about the breeding at the laboratory. But they have not yet confirmed the specific requirements that need to breed baby whales in captivity.

Naturally, baby whale fish use their electric pulse for breeding. Their breeding behavior is different from other freshwater fish species. It has several interesting facts. 

In the breeding season, male baby whales occupy shallow territories of rivers and streams. A male baby whale produces an electric pulse that has 100Hz  to 150 Hz frequency to start courtship. That signal is called a “rasp”.

If female baby whales present in their surroundings, male baby whales produce around 10 raps per minute. They do not release “rasp” signals when females are absent.  

Then female baby whales start the courtship around the male fish nest region. Male fish show some aggressive behavior in this stage.

Both male and female baby whales release some sex-specific pulse until the courtship and spawning period. The female fish releases hundreds of eggs per one spawn. 

How many babies do baby whale fish have?

Generally they lay around 100- 150 eggs per one spawn. There are 70-80 larvaes that survive. But this survival rate can differ with environmental factors such as predatory activities and water condition.The larvae stage of baby whales also can produce an electric pulse. They use it to find prey, navigation, and protection from predators.

What fish can live with baby whale fish in an aquarium?

Baby fish can live in a community tank. Generally, they have very peaceful behaviors. Below I mention the well-matching tank matescies for a baby whale.

  • Elephant Noses
  • African Black
  • Knife fish
  • Synodontis Catfish
  • Clown Loaches
  • Gouramis
  • Angels

Baby whale fish price?

The price of a baby whale depends on the size of the fish. You can purchase 4 inches size baby whale fish for around $20.

Elephant fish varieties?

There are few recognized species of Elephant fish (Genus: Brienomyrus) in the family Mormyridae.  Those are;

Ray fin fishBrienomyrus adustus 

Not widely used in the aquarium industry. They live in West Africa and their natural habitat is the same as blue whales’ habitats. The feeding behaviors and physical appearance quitely same as those two species.

Baby whale – –Brienomyrus  brachyistius

Niger delta Elephant fish– –Brienomyrus longianalis 

This variety also can produce electric pulses and they also have electric organs. Niger delta Elephant fish have the same outer appearance similar to the baby whales. But their mouths are different from baby whale fish. Niger delta Elephant fish have a pointed mouth. Niger delta Elephant fish also rear in freshwater aquariums and they need the same water quality parameters that are used for baby whales.

Will baby whale fish eat cleaner shrimp?

Baby whale fish are carnivores. Thus, they can eat invertebrates. If cleaner shrimp are matching with their mouth size, the baby whale will eat them. They cannot eat large adult cleaner shrimp. Further, you can provide hiding places for shrimp.

Aquatic plants, rocks, and ornaments can be used to decorate your aquarium. Then your baby shrimp can live peacefully. 

baby whale fish facts

They are not a mammals

Not true whales

They got this name because of their appearance

Baby whales are intelligent and they have large brain compare with their size

They have special organs to produce electricity

That small pulse of electricity signal use to communicate with each other

Also, electric signals use to protect from predators

Baby whales can release electric pulse that ranges from 100 Hz-150 Hz

Male and female can distinguish from their signals waves

They have special behaviors in the courtship period

Male fish release some pulse with the high-frequency level in during the spawning period

Female fish identify suitable male by analyzing those electric pulse frequency

The larvae stage of Baby shrimp also has an electric signal-producing organ and they use it for protection from predators.

Baby fish are egg bearing fish

Breeding baby whales is a bit difficult in captivity

Credit to : Aqua Discovery
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About Dr.Chamika

Hello, I'm Dr. Chamika. I am a Researcher in Water quality, Aquatic organisms, and Environmental chemistry. I am a passionate fish keeper, with10 years of experience. My mission is to help other aquarists experience the joy of fish keeping.