West African lungfish are prehistoric animals. They have survived unchanged for so long (nearly 400 million years) that they are sometimes nicknamed “living fossils.” West African lungfish have remarkable adaptations that have helped them survive: a primitive lung and the ability to survive in a state of estivation, which is similar to hibernation.
A lungfish’s lung is a biological adaptation. A biological adaptation is a physical change in an organism that develops over time. Like all fish, lungfish have organs known as gills to extract oxygen from water. The biological adaptation of the lung allows lungfish to also extract oxygen from the air.
A lungfish’s estivation also includes a behavioral adaptation. A behavioral adaptation describes a way an organism acts. Prior to estivation, lungfish furiously burrow into the muddy ground. The behavioral adaptation of burrowing allows lungfish to create a protected habitat where they can survive during a long period of dormancy.
Watch this video, from the Nat Geo WILD series “Destination Wild,” and use our glossary to help answer questions in the Questions tab. Learn more about these fascinating fish with our Fast Facts.
How has the West African lungfish’s primitive lung helped the species survive for more than 300 million years?
How has the West African lungfish’s estivation behavior helped the species survive for more than 300 million years?
The West African lungfish digs its burrow using its mouth. It chews through the moist earth, excreting the mud through its gills.
West African lungfish have a very slow metabolism. This means they are much less active than other fish, and often rest at the bottom of a lakebed or riverbed. In fact, West African lungfish are so inactive that many aquarium owners mistakenly think their fish is dead!
The largest specimen of West African lungfish was a meter (3.3 feet) long and weighed a whopping 4 kilograms (nearly 9 pounds).
The West African lungfish is an omnivore. It feeds on everything from frogs, fish, and mollusks to tree roots and seeds. Although larger fish and mammals may prey on juvenile lungfish, the adult lungfish has no major predators.
There are four species of African lungfish. (The one in the Destination Wild video is the West African lungfish, found in freshwater habitats throughout sub-Saharan Africa.) Other species of lungfish are indigenous to Australia and South America.
Term Part of Speech Definition Encyclopedic Entry adaptation Noun
a modification of an organism or its parts that makes it more fit for existence. An adaptation is passed from generation to generation.
Encyclopedic Entry: adaptation air Noun
layer of gases surrounding Earth.
Encyclopedic Entry: air aquatic Adjective
having to do with water.
behavioral adaptation Noun
way an organism acts in order to survive or thrive in its environment.
biological adaptation Noun
physical change in an organism that results over time in reaction to its environment.
to dig a small hole or tunnel.
silky covering spun by silkworms and other insect larvae in which they live and develop during the pupal stage.
to use up.
process in breaking down ingested food into easily absorbed and assimilated substances by the action of enzymes and other agents.
state of minimal growth or activity.
dry season Noun
time of year with little precipitation.
soil or dirt.
estivation Noun inactive state resembling deep sleep, in which some animals living in hot climates pass the summer. excrete Verb
to discharge a substance from the body.
to pull out.
having a wild or violent passion.
gills Plural Noun
respiratory organs that draw oxygen from water and into the bloodstream.
environment where an organism lives throughout the year or for shorter periods of time.
Encyclopedic Entry: habitat hibernation Noun
state of reduced physiological activity, similar to sleep, in which some animals spend the winter.
body of water surrounded by land.
Encyclopedic Entry: lake landscape Noun
the geographic features of a region.
Encyclopedic Entry: landscape living fossil Noun
organism that is a living example of an otherwise extinct group or that has remained virtually unchanged in structure and function over a long period of time.
organ in an animal that is necessary for breathing.
chemical changes in living cells by which energy is provided for vital processes.
mucus adjective, noun
slimy, fluid secretion of some animals.
tissue found in animals that expands and contracts, allowing movement.
substance an organism needs for energy, growth, and life.
Encyclopedic Entry: nutrient obtain Verb
to get or take possession of.
living or once-living thing.
having to do with the body.
small body of water surrounded by land.
period of time that occurred before the invention of written records.
to assemble or get ready for something.
simple or crude.
before or ahead of.
to take action to prevent injury or attack.
rainy season Noun
time of year when most of the rain in a region falls.
unusual and dramatic.
to renew or bring back to an earlier position or state of health.
cells that form a specific function in a living organism.