15 Fin-tastic Facts About The Whalefish For Kids

To learn more about this species, read these whalefish facts.

The Whalefish, also known as Cetomimiformes, is distributed in three different families Barbouriidae, Cetomimidae, Rondeletiidae. Some whalefish include the redmouth whalefish and the velvet whalefish. These are deep-sea fish and the whalefish habitat consists of temperate and tropical parts of the ocean and thus, can be found in such parts of the world's oceans. This fish is not well-studied and thus, not a lot of information is available about the reproduction of this fish. As the name suggests, whalefishes look like whales but the whalefish size is much smaller. They are known to have gaping mouths and are known to have no scales or fins. They are known to have a deep lateral line on their bodies that helps them to detect vibrations in the ocean. This fish is also known to have no swim bladder. Males do not have mouths that open, while it is different in a female as a female can consume through their mouth. The whalefish diet consists of marine crustaceans and plankton. Adults of the Cetomimidae family are known as flabby whalefish and juveniles as tapetails because of the tail.  Earlier it was believed that the flabby whalefish is another species. One relative is the velvet whalefish.

Continue reading for more fascinating facts about this deep-sea fish and if you are interested, you can visit our other articles about the  rainbow trout and gar.


Fact File

What do they prey on?


What do they eat?


Average litter size?


How much do they weigh?


How long are they?

1.4-15.5 in (3.5-40 cm)

How tall are they?


What do they look like?

Tropical and temperate latitudes

Skin Type

Slimy and wet scales

What are their main threats?


What is their conservation status?

Not Evaluated

Where you'll find them








Scientific Name



Barbouriidae, Cetomimidae, Rondeletiidae


Gyrinomimus, Cetomimus, Rhamphocetichthys

Whalefish Interesting Facts

What type of animal is a whalefish?

The whalefish is a deep-sea fish.

What class of animal does a whalefish belong to?

Whalefish belong to the class of Actinopterygii or ray-finned fishes and are known to be deep-sea fishes.

How many whalefishes are there in the world?

There has been no specific number of the global population of whalefish recorded. This fish is not well studied so it is difficult to find an exact number.

Where does a whalefish live?

This family of deep-sea whalefish is spread throughout the temperate and tropical parts or regions of the world's oceans.

What is a whalefish's habitat?

The habitat of this whalefish is known to be temperate and tropical parts of the oceans and are deep-sea fishes.

Who do whalefish live with?

Not much is known about whether these fish live alone or in groups.

How long does a whalefish live?

The exact lifespan of whalefishes is unknown.

How do they reproduce?

Not much information is available about the reproduction of this species in science, but it is known that a young one or juvenile is called a tapetail, whereas the adult is known as flabby whalefish. The male and female roles are unclear.

What is their conservation status?

The conservation status of the whalefish species is Not Evaluated.  

Whalefish Fun Facts

What do whalefishes look like?

This fish is known to have a body just like a whale and tends to have a gaping mouth. They are known to have no scales or fins. Also, they have a deep lateral line on their bodies that helps them to detect vibrations in the ocean. This fish is also known to have no swim bladder. The young one or juvenile or the tapetails is called so because of their streamer-like and long tail. Not much is known about the difference in physical appearance between the males and females of this family or fish.

The size and mouths of this fish are some of its recognizable features.
* Please note that this is an image of a squirrelfish, not a whalefish. If you have an image of a whalefish, please let us know at

How cute are they?

This species is not considered cute by people.

How do they communicate?

Not enough information is available about the communication of this species, but it is believed that just like other fish species, these fish also use chemical and tactile cues to communicate.

How big is a whalefish?

The males of this fish family are known to grow up to 1.4 in (3.5 cm), whereas a female can be 10 times larger than the male. The largest species was around 15.5 in (40 cm). These fish are tiny as they are smaller than most other fish species like the blobfish and the toadfish in length. This fish is known to be quite tiny compared to a whale!

How fast can a whalefish swim?

The exact speed of this fish species is unknown.

How much does a whalefish weigh?

The weight of this fish species is unknown.

What are the male and female names of the species?

No specific names are given for the males and females of the whalefish species.

What would you call a baby whalefish?

There is no particular name for a baby of this species but in general, they are referred to as a young one or juvenile.

What do they eat?

The feeding of this fish mainly consists of plankton and marine crustaceans.

Are they dangerous?

Not enough is known about this family of fish to say whether it is dangerous.

Would they make a good pet?

Not much information is available about these fish as pets. However, they are deep sea fishes and are found in deep water where it is completely dark, so it is unlikely that humans could replicate their environment at home.

Did you know...

Adults of the Cetomimidae family are referred to as flabby whalefish and the juveniles as tapetails and were initially thought to be of different families.

It is believed that around nine females of this whalefish would measure an equal length to the smallest whale.

Cetomimidae is known to be the most diverse in the family of whalefish.

One unique feature about this fish is that the male whalefish cannot open its mouth or jaws and thus, it cannot consume food in its adult phase. To take in nutrients continuously through a food source, the males of this fish retain the shells of the prey captured in their juvenile phase and continue to feed on those shells as a food and nutrients source for their life.

Whereas it is interesting to note that the females of this fish species can feed on food. They have a stomach that is expandable and large mouths or jaws. They are able to consume and digest large prey which can be too large to consume sometimes. They are also known to hold their prey until the food is able to digest itself.

It is unknown if this fish is Endangered or not as this fish has not been studied extensively and thus, its status is unknown.

How have whalefish adapted to their environment?

This fish is known to be found in extremely deep water where it is black. It has been recorded that these fish have developed an advanced sensory system that helps them detect slight vibrations in the ocean and thus, figure out objects in their surroundings and helps them avoid or escape from potential predator attacks.

Why is it called a whalefish?

These fish are called whalefish because they look similar to whales, but are much smaller than a whale and thus, are referred to as whalefish.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other fish from our monkfish facts and green sunfish facts pages.

You can even occupy yourself at home by coloring in one of our free printable fish coloring pages.

* Please note that this is an image of a squirrelfish, not a whalefish. If you have an image of a whalefish, please let us know at



At Kidadl we pride ourselves on offering families original ideas to make the most of time spent together at home or out and about, wherever you are in the world. We strive to recommend the very best things that are suggested by our community and are things we would do ourselves - our aim is to be the trusted friend to parents.

We try our very best, but cannot guarantee perfection. We will always aim to give you accurate information at the date of publication - however, information does change, so it’s important you do your own research, double-check and make the decision that is right for your family.

Kidadl provides inspiration to entertain and educate your children. We recognise that not all activities and ideas are appropriate and suitable for all children and families or in all circumstances. Our recommended activities are based on age but these are a guide. We recommend that these ideas are used as inspiration, that ideas are undertaken with appropriate adult supervision, and that each adult uses their own discretion and knowledge of their children to consider the safety and suitability.

Kidadl cannot accept liability for the execution of these ideas, and parental supervision is advised at all times, as safety is paramount. Anyone using the information provided by Kidadl does so at their own risk and we can not accept liability if things go wrong.

Sponsorship & Advertising Policy

Kidadl is independent and to make our service free to you the reader we are supported by advertising.

We hope you love our recommendations for products and services! What we suggest is selected independently by the Kidadl team. If you purchase using the buy now button we may earn a small commission. This does not influence our choices. Please note: prices are correct and items are available at the time the article was published.

Kidadl has a number of affiliate partners that we work with including Amazon. Please note that Kidadl is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.

We also link to other websites, but are not responsible for their content.

Read our Sponsorship & Advertising Policy
Get The Kidadl Newsletter

1,000 of inspirational ideas direct to your inbox for things to do with your kids.

Thank you! Your newsletter will be with you soon.
Oops! Something went wrong while submitting the form.
No items found.
No items found.